[1] : The Collaborative International Dictionary of English v.0.48

flunk \flunk\ flu^ngk, v. i. imp.  p. p. flunked
   flu^ngkt; p. pr.  vb. n. flunking. cf. funk.
   to fail, as on a lesson; to back out, as from an undertaking,
   through fear.
   1913 webster
see also:
flunked flunking funk 

[2] : The Collaborative International Dictionary of English v.0.48

flunk \flunk\, v. t.
   1. to fail in; to fail to pass a test, examination, or
      course of study. colloq. u.s.
      1913 webster +pjc

   2. to shirk, as a task or duty.
      1913 webster

[3] : The Collaborative International Dictionary of English v.0.48

flunk \flunk\, n.
   a failure or backing out; specifically college cant, a
   total failure in a recitation. u.s.
   1913 webster

[4] : WordNet (r) 2.0

flunk
     v : fail to get a passing grade; "she studied hard but failed
         nevertheless"; "did i fail the test?" syn: fail, bomb,
          flush it ant: pass
see also:
fail bomb flush it pass 

[5] : Moby Thesaurus II by Grady Ward, 1.0

23 moby thesaurus words for "flunk":
   be found wanting, be unsuccessful, bollix, botch, bungle, bust,
   come to grief, fail, fail of success, fiasco, flunk out, foozle,
   go bankrupt, hash, labor in vain, lose, mess, muddle, not come off,
   not pass, not work, wash out, washout

Flunk >> F Words
Flunk, definition of term: Flunk
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