'Setback' definitions:

Definition of 'setback'

(from WordNet)
noun
An unfortunate happening that hinders or impedes; something that is thwarting or frustrating [syn: reverse, reversal, setback, blow, black eye]

Definition of 'Setback'

From: GCIDE
  • Setback \Set"back`\ (s[e^]t"b[a^]k`), n.
  • 1. (Arch.) Offset, n., 4. [1913 Webster]
  • 2. A backset; a countercurrent; an eddy. [U. S.] [1913 Webster]
  • 3. A reversal of progress in an endeavor; a reverse; a backset; a check; a repulse; a relapse. [Colloq. U.S.] [1913 Webster]

Synonyms of 'setback'

From: Moby Thesaurus