# Scientific and technical terms: technology, medicine, science, geography, mathematics and language

> These study notes explain Scientific and technical terms for the Group 4 / VAO (Combined Civil Services Examination-IV) exam in plain language: the same reviewed notes the TNPSC Guide app shows, published by our editors with their source. Read the key points first, then practise the unit's questions. For exam facts such as dates and vacancies, always check tnpsc.gov.in.

Last updated: 2026-11-02 · By TNPSC Guide editorial team
URL: https://www.tnpscguide.com/exams/group-4/notes/tamil-technical-terms-science

## Why the exam asks this

Unit IV of the syllabus asks for the exact Tamil words for technical terms of many fields, including science, education, medicine, management, law, geography, technology, media and information technology; the unit has 10 questions. The 2024 paper (subject code 003) has no question marked for this unit. In the 2025 paper, science and technology term questions came in two forms: the exact Tamil for one word (Q30, 33, 80, 81, 94) and match four pairs (Q29, 83). So this lesson first gives the syllabus and textbook words for the one-word question, then the look-alike pairs that suit a match question.

## What is a technical term?

As times change and a field makes new discoveries, the words made and used for them are technical terms (kalaichchorkal); the class 11 textbook says they are mostly names given for a reason. For one English word (cellphone) three Tamil words are in use: kaipesi, sellidappesi and alaipesi; this way of making words is called kalaichchollaakkam. A new word should be a Tamil word, fit the meaning, be short and simple, sound pleasant and follow Tamil grammar. Example: on a bus, whether someone says alaipesi or kaipesi, they mean the same device.

**Ways of making terms shown by the scholar Va. Se. Kuzhandhaisamy**

| | |
| --- | --- |
| using an old literary word | valavan (pilot) |
| using a spoken word | ammai (measles) |
| borrowing a word from another language | thasama murai (decimal) |
| coining a new word | moolakkooru (molecule) |
| accepting world usage | eks kathir (X-ray) |
| translating a term of another language | olichcherkkai (photosynthesis) |
| transliterating | meettar, om (metre, ohm) |

## The one-word question: the syllabus and irrigation

Learn the syllabus's five examples first: thedu pori (search engine), valasai (migration), ovvaamai (allergy), marabanu (gene), kadal mail (nautical mile). The class 9 box prints the same word joined, kadalmail. The answer to 2025 Q94 (irrigation technology) was neerppaasanath thozhilnutpam; the class 9 box has paasanath thozhilnutpam; the class 10 box has only paasanam (irrigation). The option may not match the textbook form letter for letter; choose by the meaning. Example: when we talk about new ways of taking water to a field through pipes, the word paasanath thozhilnutpam comes up.

## Inaiyam and valaiththalam: textbook usage and official usage

For new Tamil words made as science and technology grow, the class 6 textbook gives inaiyam, muganool, pulanam, kuralthedal, thedupori, seyali and thoduthirai as examples. Take care with inaiyam. The class 11 textbook gives inaiyam, valaippoo (website, blog); the official glossary gives valaiththalam (website) and inaiyathalam, inaiyam (internet). So do not take inaiyam alone as the answer for website; the glossary form is valaiththalam. Example: to open a company's website (valaiththalam) your phone needs an internet connection (inaiya inaippu).

**Technology terms**

| | |
| --- | --- |
| website, blog | inaiyam, valaippoo (class 11) |
| website (official glossary) | valaiththalam |
| internet (official glossary) | inaiyathalam, inaiyam |
| e-mail / smartphone / Windows 10 / 8G | minnanjal / thiranpesi / palagani 10 / ettaam thalaimurai (class 11) |
| smartphone / touch screen / bug | thiranpesi / thoduthirai / pizhai (class 11) |
| sub junior / super senior / carrom / referee | miga ilaiyor / meemooththor / naalaanguzhi aattam / naduvar (class 11) |
| nanotechnology / space technology / biotechnology | meenunthozhilnutpam / vinvelith thozhilnutpam / uyirith thozhilnutpam (class 10) |
| cosmic rays / ultraviolet rays / infrared rays | vinvelik kathirgal / pura oothaak kathirgal / agachchivappuk kathirgal (class 10) |
| launch vehicle / missile / nautical mile | evu oorthi / evugani / kadalmail (class 9) |
| video conference / download / passenger name record / electronic devices | kaanolik koottam / pathivirakkam / payaniyar peyarp pathivu / minnanuk karuvigal (class 9) |

## Medicine and biology

Medical terms are in the class 8 and class 11 Tamil books and in the word list of the class 10 Science book (pages 350-351). One English word has two printed forms: for X-ray the class 11 textbook gives oodukathir on page 167 and eks kathir, taken from world usage, on page 168; both are correct. Swapping kittappaarvai (myopia) and thoorappaarvai (hypermetropia) is a trap in match questions. For amaippu oththa uruppugal (homologous organs) and seyal oththa uruppugal (analogous organs), the first word, amaippu or seyal, makes the difference. Example: if letters near you are clear but the number of a far-off bus is blurred, that is kittappaarvai.

**Medical terms**

| | |
| --- | --- |
| clinic / blood group / pharmacist | maruththuvamanai / kuruthippirivu / marundhaalunar (class 11) |
| X-ray / typhoid / ointment | oodukathir / kudarkaaychchal / kalimbu (class 11) |
| disease / herbs / millets / side effect | noy / mooligai / siruthaaniyangal / pakkavilaivu (class 8) |
| antibiotic / gene / allergy | nunnuyir muri / marabanu / ovvaamai (class 8) |
| myopia / hypermetropia | kittappaarvai / thoorappaarvai (class 10 Science) |
| anemia / goitre / gigantism / dwarfism | iraththasogai / munkazhuththuk kazhalai / asuraththanmai / kullath thanmai (class 10 Science) |
| oncology / carcinogens / stem cell | putrunoyiyal / putru noyk kaarani / moolach sel (class 10 Science) |
| pacemaker / reflex action / medulla oblongata / cerebrospinal fluid | ithaya iyakkam seeraakki / anichchaich seyal / mugulam / moolai thandu vada thiravam (class 10 Science) |

**Biology terms (class 10 Science)**

| | |
| --- | --- |
| mutation / genotype / genetic engineering / dihybrid cross | saduthi maatram / marabu vagai / marabup poriyiyal / iru panbu kalappu |
| homologous organs / analogous organs / vestigial organs | amaippu oththa uruppugal / seyal oththa uruppugal / echcha uruppugal |
| placenta / umbilical cord / zygote / parturition | thaai sei inaippuch thisu / thoppul kodi / karuvutra muttai / kuzhandhaip pirappu |
| stomata / abscission / apical dominance / geotropism / fossils | ilaiththulai / uthirthal / nuni aathikkam / puvieerppu saarbu / puthai uyir padimam |

## Physics and chemistry

These words are in the word list of the class 10 Science book (pages 350-351). Watch the pairs that share a first word: anukkaru inaivu (nuclear fusion), anukkaru pilavu (nuclear fission), anukkaru ulai (nuclear reactor). Three for sound: kutroli (infrasonic), meeyoli (ultrasonic), seviyunar oli (audible). Neer eerkkum porul (hygroscopic substance) and neer eerththu karaiyum porul (deliquescent substance): the one word karaiyum makes the difference. Example: at a temple festival the song from the loudspeaker reaches our ears; that is seviyunar oli.

**Physics and chemistry terms (class 10 Science)**

| | |
| --- | --- |
| nuclear fusion / nuclear fission / nuclear reactor / radioactivity | anukkaru inaivu / anukkaru pilavu / anukkaru ulai / kathiriyakkam |
| refraction / scattering / dispersion / spectrum | oli vilagal / olichchitharal / nirappirigai / niramaalai |
| infrasonic sound / ultrasonic sound / audible sound | kutroli / meeyoli / seviyunar oli |
| alternating current / resistivity / electric potential / short circuit / earthing | maaruthisai minnottam / minthadai en / minnazhuththam / kurukkuth thadachchutru / puviyinaippu |
| saturated solution / unsaturated solution / super saturated solution / aqueous | thevittiya karaisal / thevittaatha karaisal / athi thevittiya karaisal / neerkkaraisal |
| hygroscopic substance / deliquescent substance | neer eerkkum porul / neer eerththu karaiyum porul |
| redox reaction / vapour density / ductility / froth floatation | aaksijanetra odukka vinai / aavi adarththi / kambiyaaga neettuthal / nurai mithappu murai |
| renewable energy / non-conventional energy resource / green revolution / social forestry | puthuppikkath thakka valam / marabu saaraa aatral valangal / pasumai puratchi / samuthaayak kaadugal |

## Geography and weather

Puyal (storm), sooraavali (tornado), perungaatru (tempest) and suzhalkaatru (whirlwind) are in one term box of class 10; they suit a match question. Keep nilakkaatru (land breeze) and kadarkaatru (sea breeze) in their places too. One first word can also lead to different English words: vinvelith thozhilnutpam (space technology), vinvelik kathirgal (cosmic rays). Example: on the Marina, the wind that blows from the sea towards the land is kadarkaatru.

**Geography terms**

| | |
| --- | --- |
| storm / tornado / tempest | puyal / sooraavali / perungaatru (class 10) |
| land breeze / sea breeze / whirlwind | nilakkaatru / kadarkaatru / suzhalkaatru (class 10) |
| plain / valley / ridge / thicket / tribes | samaveli / pallaththaakku / malaimugadu / puthar / pazhangudiyinar (class 8) |
| conical stone / water management / irrigation technology / tropical zone | kumizhik kal / neer melaanmai / paasanath thozhilnutpam / veppa mandalam (class 9) |
| irrigation / territory | paasanam / nilappaguthi (class 10) |
| saline soil | kalarnilam (class 9) |

## Mathematics terms

These words are in the mathematics term list of the class 10 Mathematics book (pages 358-359). Keep atcharegai (latitude) and theerkkaregai (longitude), and etrak konam (angle of elevation) and irakkak konam (angle of depression), in their places. Pothu viththiyaasam (common difference) belongs to the arithmetic progression (koottuththodar varisai); pothu vigitham (common ratio) belongs to the geometric progression (perukkuththodar varisai). Example: the angle at which you look up from the foot of a hill at the temple on top is etrak konam; the angle at which you look down from the top at the village is irakkak konam.

**Mathematics table (class 10 Mathematics)**

| | |
| --- | --- |
| latitude / longitude / great circle / hemisphere / geo-positioning system | atcharegai / theerkkaregai / meepperu vattam / araik kolam / puvi nilaippaduththal amaippu |
| angle of elevation / angle of depression / theodolite / clinometer | etrak konam / irakkak konam / thalamattak konamaani / saayvumaani |
| kadhams (a unit of distance) | kaadhamgal |
| arithmetic progression / geometric progression / common difference / common ratio | koottuththodar varisai / perukkuththodar varisai / pothu viththiyaasam / pothu vigitham |
| standard deviation / variance / coefficient of variation / range | thitta vilakkam / vilakka varkka saraasari / maarupaattuk kezhu / veechchagam allathu veechchu |
| sample space / event / random experiment / mutually exclusive events | kooruveli / nigazhchchi / samavaayppuch sothanai / ondraiyondru vilakkum nigazhchchigal |

## Language terms

Two classes give two forms for one English word: for vowel, uyiroli in class 8 and uyirezhuththu in class 10; for consonant, meyyoli and meyyezhuththu. Both are textbook forms. Oliyan (phoneme) comes in both the class 8 and the class 9 boxes; in class 9 uruban (morpheme) comes with it. For philosophy, class 9 gives both, meyyiyal (thaththuvam). Example: the big book you turn in a library to look up the meanings of words is a perakaraathi (lexicon).

**Language and education terms**

| | |
| --- | --- |
| articulatory phonetics / vowel / consonant / nasal consonant sound / phoneme | olipirappiyal / uyiroli / meyyoli / mookkoli / oliyan (class 8) |
| lexicography / pictograph / epigraph | agaraathiyiyal / siththira ezhuththu / kalvettu (class 8) |
| morpheme / phoneme / comparative grammar / lexicon | uruban / oliyan / oppilakkanam / perakaraathi (class 9) |
| vowel / consonant / homograph / monolingual / conversation / discussion | uyirezhuththu / meyyezhuththu / oppezhuththu / oru mozhi / uraiyaadal / kalandhuraiyaadal (class 10) |
| reforming the letters / font / philosophy / syllable / rhyme | ezhuththuch seerthiruththam / ezhuththuru / meyyiyal (thaththuvam) / asai / iyaibuth thodai (class 9) |
| note book / answer book / rough note book / prospectus (education) | ezhuthusuvadi / vidaichchuvadi / pothuk kurippuch chuvadi / vilakkachchuvadi (class 11) |

## Literature terms

The class 10 box gives the kinds of literature as: sevvilakkiyam, kaappiya ilakkiyam, bakthi ilakkiyam, pandaiya ilakkiyam, vattaara ilakkiyam, naattuppura ilakkiyam, naveena ilakkiyam; learn the whole list. For classical literature, class 9 gives sevviyal ilakkiyam and class 10 gives sevvilakkiyam; both are textbook forms. Example: the person who wrote the play for the school day is the naadaga aasiriyar (playwright); the one who tells the same story on stage is the kathai solli (storyteller).

**Literature table**

| | |
| --- | --- |
| free verse / simile / metaphor | kattilaak kavithai / uvamaiyani / uruvaga ani (class 9) |
| personality / humane / cultural academy | aalumai / manitham / panpaattuk kazhagam (class 9) |
| classical / epic / devotional / ancient literature | sevvilakkiyam / kaappiya ilakkiyam / bakthi ilakkiyam / pandaiya ilakkiyam (class 10) |
| regional / folk / modern literature | vattaara ilakkiyam / naattuppura ilakkiyam / naveena ilakkiyam (class 10) |
| playwright / screenplay / storyteller / aesthetics | naadaga aasiriyar / thiraikkathai / kathai solli / azhagiyal allathu murugiyal (class 10) |
| emblem / thesis / intellectual / symbolism | sinnam / aayvedu / arivaalar / kuriyeettiyal (class 10) |
| punctuation / translation / ornament / awareness / talent / reform | niruththakkuri / mozhipeyarppu / anigalan / vizhippunarvu / thiramai / seerthiruththam (class 8) |

## History and culture

Notice that adding iyal gives the name of a field: kalvettu (epigraph), kalvettiyal (epigraphy); putrunoyiyal (oncology). Do not mix porippu (inscription) up with them. For philosophy, class 8 gives thaththuvam; a philosopher is meyyiyalaalar. One class 9 box puts words of different fields together, such as Indhiya Thesiya Iraanuvam (Indian National Army) and karumbuch chaaru (sugarcane juice); learn those pairs too. Example: the memorial stone of a hero at the edge of a village is a nadukal (hero stone).

**History and culture table**

| | |
| --- | --- |
| excavation / epigraphy / hero stone | agazhaayvu / kalvettiyal / nadukal (class 9) |
| cultural symbol / embossed sculpture / inscription | panpaattuk kuriyeedu / pudaippuch chirpam / porippu (class 9) |
| cave temple / honorary doctorate / melody / document short film / combination | kudaivaraik kovil / mathippuru munaivar / mellisai / aavanak kurumpadam / punarchchi (class 9) |
| Indian National Army / classical literature / commodity exchange / sugarcane juice / vegetable soup | Indhiya Thesiya Iraanuvam / sevviyal ilakkiyam / pandamaatrumurai / karumbuch chaaru / kaaygari vadisaaru (class 9) |
| charity / integrity / saint / rational / philosophy | thondu / nermai / gnaani / pagutharivu / thaththuvam (class 8) |
| belief / philosopher / renaissance / revivalism | nambikkai / meyyiyalaalar / marumalarchchi / meettuuruvaakkam (class 10) |
| crafts / flute / drum / basketry / artisan | kaivinaip porulgal / pullaanguzhal / murasu / koodaimudaithal / kaivinaignar (class 8) |
| thread / loom / dairy farm / tanning / dyeing / readymade dress | nool / thari / paalpannai / thol pathaniduthal / saayam etruthal / aayaththa aadai (class 8) |

**Key facts**

| | |
| --- | --- |
| Unit IV questions | 10 (syllabus, page 3) |
| Syllabus examples | thedu pori, valasai, ovvaamai, marabanu, kadal mail (syllabus, page 3) |
| cellphone | kaipesi, sellidappesi, alaipesi (class 11, page 166) |
| X-ray | oodukathir (class 11, page 167); eks kathir (page 168) |
| website | valaiththalam (official glossary, volume 3, page 510); inaiyam (class 11, page 166) |
| internet | inaiyathalam, inaiyam (official glossary, volume 2, page 242) |
| irrigation technology (2025, Q94) | paasanath thozhilnutpam (class 9, page 62); 2025 answer: neerppaasanath thozhilnutpam |
| Science word list | class 10 Science, pages 350-351 |
| Mathematics term list | class 10 Mathematics, pages 358-359 |

> **Exam tip:** Memory hooks
Adding iyal gives a field: kalvettu, kalvettiyal; putrunoy, putrunoyiyal. With karaiyum it is deliquescent; without it, hygroscopic. Amaippu alike is homologous; seyal alike is analogous. The koottu (adding) progression has a common difference; the perukku (multiplying) progression has a common ratio. For website the glossary form is valaiththalam; do not take inaiyam alone as the answer.

**Easy to confuse**

| | |
| --- | --- |
| neer eerkkum porul / neer eerththu karaiyum porul | hygroscopic / deliquescent; the word karaiyum makes the difference |
| kittappaarvai / thoorappaarvai | myopia / hypermetropia; a swapped pair is a trap in match questions |
| kutroli / meeyoli / seviyunar oli | infrasonic / ultrasonic / audible |
| anukkaru inaivu / anukkaru pilavu / anukkaru ulai | fusion / fission / reactor |
| amaippu oththa / seyal oththa / echcha uruppugal | homologous / analogous / vestigial |
| atcharegai / theerkkaregai | latitude / longitude |
| etrak konam / irakkak konam | angle of elevation / angle of depression |
| pothu viththiyaasam / pothu vigitham | common difference (arithmetic progression) / common ratio (geometric progression) |
| uyiroli, uyirezhuththu / meyyoli, meyyezhuththu | vowel / consonant; class 8 and class 10 forms, both correct |
| oliyan / uruban | phoneme / morpheme |
| kalvettu / kalvettiyal / porippu | epigraph / epigraphy / inscription |
| thaththuvam / meyyiyal (thaththuvam) / meyyiyalaalar | philosophy (class 8) / philosophy (class 9) / philosopher |
| oodukathir / eks kathir | both X-ray (class 11, pages 167, 168) |
| puyal / sooraavali / perungaatru / suzhalkaatru | storm / tornado / tempest / whirlwind; they suit a match question |
| vinvelith thozhilnutpam / vinvelik kathirgal | space technology / cosmic rays; same first word, different English |
| paasanath thozhilnutpam / paasanam | irrigation technology (class 9) / irrigation (class 10) |
| sevviyal ilakkiyam / sevvilakkiyam | classical literature: class 9 / class 10; both textbook forms |
| valaiththalam / inaiyathalam, inaiyam | website / internet (official glossary); class 11 gives inaiyam, valaippoo for website, blog |

> **Exam tip:** Quick check
1. What is the Tamil for deliquescent substance? Answer: neer eerththu karaiyum porul.
2. What word does the official glossary give for website? Answer: valaiththalam.
3. Paasanath thozhilnutpam (irrigation technology) is a word of which class's box? Answer: class 9.
4. Which progression has a common ratio? Answer: the geometric progression (perukkuththodar varisai).
5. Which term, made from an old literary word, stands for pilot? Answer: valavan.

Source: ஒருங்கிணைந்த குடிமைப் பணிகள் தேர்வு-IV (தொகுதி-IV பணிகள்) பாடத்திட்டம், குறியீடு 496 (TNPSC Group 4 syllabus, Tamil PDF) (பாடத்திட்டம் (குறியீடு 496) பக்கம் 3, அலகு IV; 6ஆம் வகுப்புத் தமிழ், முதல் பருவம், இயல் 1, பக்கம் 11; 8, 9, 10ஆம் வகுப்புத் தமிழ், கலைச்சொல் அறிவோம் (8: பக்கம் 22, 42, 68, 92, 117, 142, 187; 9: பக்கம் 30, 62, 94, 121, 149, 175, 207, 230, 252; 10: பக்கம் 24, 48, 69, 97, 126, 153, 182, 200); 10ஆம் வகுப்பு அறிவியல், சொல்லடைவு, பக்கம் 350-351; 10ஆம் வகுப்புக் கணிதம், கணித கலைச் சொற்கள், பக்கம் 358-359; 11ஆம் வகுப்புப் பொதுத் தமிழ், இயல் 6 கலைச்சொல்லாக்கம், பக்கம் 166-168; ஆட்சிச் சொல்லகராதி (திருந்திய பதிப்பு, 2022) தொகுதி 2 பக்கம் 242, தொகுதி 3 பக்கம் 510)

## Sources

- [Official syllabus page](https://www.tnpsc.gov.in/english/syllabus.html)
- [Notifications](https://www.tnpsc.gov.in/English/Notification.aspx)