a weak, ineffectual, timid person.

Verb Phrases

wimp out,
  1. to be or act like a wimp.
  2. to show timidity or cowardice; chicken out.

Origin of wimp

1915–20, Americanism; origin uncertain; cf. whimper
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for wimp out

wimp out


(intr, adverb) informal to fail to do or complete something through fear or lack of conviction



informal a feeble ineffective personSee also wimp out
Derived Formswimpish or wimpy, adjective

Word Origin for wimp

C20: of unknown origin


acronym for

windows, icons, menus (or mice), pointers: denoting a type of user-friendly screen display used on small computersa WIMP system
physics weakly interacting massive particle
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

Word Origin and History for wimp out



1920 (but not attested again until 1960), perhaps a clipped form of whimper (cf whimp, 1540s), perhaps influenced by J. Wellington Wimpy, comparatively unaggressive character in "Popeye" comics.



1986, with out (adv.), from wimp (n.). Related: Wimped; wimping.

Online Etymology Dictionary, © 2010 Douglas Harper

wimp out in Science



Short for weakly interacting massive particle. Any of various hypothetical particles, some predicted by certain theories such as supersymmetry, which interact with other particles by the force of gravity alone. WIMPs are considered by some scientists to be candidates for the dark matter that makes up much of the mass of the universe.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.