WordNet (r) 3.0 (2006):

trial run
    n 1: trying something to find out about it; "a sample for ten
         days free trial"; "a trial of progesterone failed to
         relieve the pain" [syn: trial, trial run, test,
         tryout]

Moby Thesaurus II by Grady Ward, 1.0:

21 Moby Thesaurus words for "trial run":
   Gedankenexperiment, audition, bench test, dry run, experimentation,
   flight test, hearing, pilot plan, practical test, practice,
   rehearsal, road test, shakedown, shakedown cruise, test,
   test flight, test run, trial, trial and error, tryout, workout