1. (preposition)under in or to a position below sth The cat is under the bed.; oil reserves under the ocean
2. under below the surface of a liquid He dived under the water.
3. under less or younger than She ran the course in under 10 minutes.; prices under $2; children under six
4. under experiencing or being affected by The matter is under investigation.; students under a lot of pressure/stress; a city under attack
5. under indicates the law or rule that governs sth Under the new law, oil companies would be taxed more heavily.; The region was divided up under the treaty.
6. under indicates the person or group who controls sth a restaurant under new management; The country flourished under its new government.
7. under indicates where sth can be found in a particularsystem You'll find it under 'C' for "committees."
8. (adverb)under lower or younger kids who are six and under; no tax on items priced at $3 and under
9. under below the surface of a liquid She dived in and stayed under for a long time.
Definition of 'under'
Webster Dictionary
1. (adj)under lower in position, intensity, rank, or degree; subject; subordinate; -- generally in composition with a noun, and written with or without the hyphen; as, an undercurrent; undertone; underdose; under-garment; underofficer; undersheriff
2. (adverb)under in a lower, subject, or subordinate condition; in subjection; -- used chiefly in a few idiomatic phrases; as, to bring under, to reduce to subjection; to subdue; to keep under, to keep in subjection; to control; to go under, to be unsuccessful; to fail
3. under below or lower, in place or position, with the idea of being covered; lower than; beneath; -- opposed to over; as, he stood under a tree; the carriage is under cover; a cellar extends under the wholehouse
4. under denoting relation to some thing or person that is superior, weighs upon, oppresses, bows down, governs, directs, influences powerfully, or the like, in a relation of subjection, subordination, obligation, liability, or the like; as, to travel under a heavy load; to live under extreme oppression; to havefortitude under the evils of life; to havepatience under pain, or under misfortunes; to behave like a Christian under reproaches and injuries; under the pains and penalties of the law; the condition under which one enters upon an office; under the necessity of obeying the laws; under vows of chastity
5. under denoting relation to something that exceeds in rank or degree, in number, size, weight, age, or the like; in a relation of the less to the greater, of inferiority, or of falling short
6. under denoting relation to something that comprehends or includes, that represents or designates, that furnishes a cover, pretext, pretense, or the like; as, he betrayed him under the guise of friendship; Morpheus is represented under the figure of a boy asleep
7. under less specifically, denoting the relation of being subject, of undergoing regard, treatment, or the like; as, a bill under discussion
Definitions of under 
Afrikaans: onder
Arabic: تَحْت
Bulgarian: под
Brazilian: debaixo de
Czech: pod
German: unter
Danish: under
Greek: κάτω από
Spanish: debajo, bajo
Estonian: all, alla
Farsi: زیر
Finnish: alla
French: sous, au-dessous (de)
Hebrew: מִתַחַת לְ-
Hindi: नीचे
Croatian: ispod
Hungarian: alatt(a)
Indonesian: di bawah
Icelandic: undir
Italian: sotto
Japanese: ～の下に
Korean: (위치) …의 (바로) 밑에
Lithuanian: po
Latvian: zem
Malay: di bawah
Dutch: onder
Norwegian: under
Polish: pod
Persian: زیر
Pashto: لاندی
Portuguese: debaixo de
Romanian: sub, dedesubtul
Russian: под; на (дне)
Slovak: pod
Slovenian: pod
Serbian: ispod
Swedish: under
Thai: ใต้
Turkish: altın(d)a
Taiwanese: (位置)在...之下
Ukrainian: під
Urdu: اندر
Vietnamese: dưới, ở dưới
Chinese: （位置）在...之下
