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definitions

under-

  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. 2018
British Dictionary definitions for under-

under-

prefix
  1. below or beneathunderarm; underground
  2. of lesser importance or lower rankundersecretary
  3. to a lesser degree than is proper; insufficient or insufficientlyundercharge; underemployed
  4. indicating secrecy or deceptionunderhand
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