[ uhn-der ]
See synonyms for under on Thesaurus.com
  1. beneath and covered by: under a table; under a tree.

  2. below the surface of: under water; under the skin.

  1. at a point or position lower or further down than: He was hit just under his eye.

  2. in the position or state of bearing, supporting, sustaining, enduring, etc.: to sink under a heavy load.

  3. beneath the heading or within the category of: Classify the books under “Fiction” and “General.”

  4. as designated, indicated, or represented by: to register under a new name.

  5. below in degree, amount, etc.; less than: purchased under cost.

  6. below in rank; of less dignity, importance, or the like: A corporal is under a sergeant.

  7. subject to the authority, direction, or supervision of: a bureau functioning under the prime minister.

  8. subject to the instruction or advice of: to study the violin under Heifetz.

  9. subject to the influence, condition, force, etc., of: under these circumstances; born under the sign of Taurus.

  10. protected, controlled, or watched by: under guard.

  11. authorized, warranted, or attested by: under one's hand or seal.

  12. in accordance with: under the provisions of the law.

  13. during the rule, administration, or government of: new laws passed under President Reagan.

  14. in the state or process of: under repair; a matter under consideration.

  15. Nautical. powered by the means indicated: under sail; under steam.

  1. below or beneath something: Go over the fence, not under.

  2. beneath the surface.

  1. in a lower place.

  2. in a lower degree, amount, etc.: selling blouses for $25 and under.

  3. in a subordinate position or condition.

  4. in or into subjection or submission.

  1. beneath or on the underside: the under threads of the embroidery.

  2. lower in position.

  1. lower in degree, amount, etc.

  2. lower in rank or condition.

  3. subject to the control, effect, etc., as of a person, drug, or force: The hypnotist had her subject under at once. The patient was under as soon as he breathed the anesthetic.

Verb Phrases
  1. go under,

    • to give in; succumb; yield: She tried desperately to fight off her drowsiness, but felt herself going under.

    • to fail in business: After 20 years on the same corner they finally went under.

Idioms about under

  1. under wraps. wrap (def. 14).

Origin of under

First recorded before 900; Middle English, Old English; cognate with Dutch onder, German unter, Old Norse undir; akin to Latin inferus “lower” (cf. inferior )

synonym study For under

2. See below.

Other definitions for under- (2 of 2)


  1. a prefixal use of under, as to indicate place or situation below or beneath (underbrush; undertow); lower in grade or dignity (undersheriff; understudy); of lesser degree, extent, or amount (undersized); or insufficiency (underfeed).

Origin of under-

Middle English; Old English

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use under in a sentence

  • under the one-sixth they appear as slender, highly refractive fibers with double contour and, often, curled or split ends.

    A Manual of Clinical Diagnosis | James Campbell Todd
  • The Pontellier and Ratignolle compartments adjoined one another under the same roof.

  • The Majesty on high has a colony and a people on earth, which otherwise is under the supremacy of the Evil One.

    Solomon and Solomonic Literature | Moncure Daniel Conway
  • Poor Squinty ran and tried to hide under the straw, for he knew the boy was talking about him.

    Squinty the Comical Pig | Richard Barnum
  • For several months he remained under a political cloud, charged with incompetency to quell the Philippine Rebellion.

    The Philippine Islands | John Foreman

British Dictionary definitions for under (1 of 2)


/ (ˈʌndə) /

  1. directly below; on, to, or beneath the underside or base of: under one's feet

  2. less than: under forty years

  1. lower in rank than: under a corporal

  2. subject to the supervision, jurisdiction, control, or influence of

  3. subject to (conditions); in (certain circumstances)

  4. within a classification of: a book under theology

  5. known by: under an assumed name

  6. planted with: a field under corn

  7. powered by: under sail

  8. astrology during the period that the sun is in (a sign of the zodiac): born under Aries

  1. below; to a position underneath something

Origin of under

Old English; related to Old Saxon, Gothic undar, Old High German untar, Old Norse undir, Latin infra

British Dictionary definitions for under- (2 of 2)


  1. below or beneath: underarm; underground

  2. of lesser importance or lower rank: undersecretary

  1. to a lesser degree than is proper; insufficient or insufficiently: undercharge; underemployed

  2. indicating secrecy or deception: underhand

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Idioms and Phrases with under


In addition to the idioms beginning with under

  • under a cloud
  • under age
  • under any circumstances
  • under arrest
  • under consideration
  • under cover
  • under false colors
  • under fire
  • under lock and key
  • under one's belt
  • under one's breath
  • under one's feet
  • under one's hat
  • under one's nose
  • under one's own steam
  • under one's skin
  • under pain of
  • under par
  • under someone's spell
  • under someone's thumb
  • under someone's wing
  • under the aegis of
  • under the circumstances
  • under the counter
  • under the gun
  • under the hammer
  • under the impression
  • under the influence
  • under the knife
  • under the sun
  • under the table
  • under the weather
  • under the wire
  • under way
  • under wraps

also see:

  • below (under) par
  • born under a lucky star
  • buckle under
  • come under
  • cut the ground from under
  • don't let the grass grow under one's feet
  • everything but the kitchen sink (under the sun)
  • fall under
  • false colors, sail under
  • get under someone's skin
  • go under
  • hide one's light under a bushel
  • hot under the collar
  • keep under one's hat
  • knock the bottom out (props out from under)
  • knuckle under
  • light a fire under
  • nothing new under the sun
  • of (under) age
  • out from under
  • plow under
  • pull the rug out from under
  • put the skids under
  • six feet under
  • snow under
  • sweep under the rug
  • water over the dam (under the bridge)

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.