The Collaborative International Dictionary of English v.0.48:

Tryout \Try"out\, n.
   1. a test of the performance capability of a person, to
      ascertain fitness for a particular task; in sports, a test
      by which the fitness of a player or contestant to remain
      in a certain class is determined.
      [Webster 1913 Suppl. +PJC]

   2. (Theater) one or more performances of a play prior to the
      official opening, held at a location outside of the city
      where it is to be formally presented, conducted for the
      purpose of determining audience response or ascertaining
      weaknesses needing correction.
      [PJC]

WordNet (r) 3.0 (2006):

tryout
    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]
    2: a test of the suitability of a performer [syn: audition,
       tryout]

Moby Thesaurus II by Grady Ward, 1.0:

81 Moby Thesaurus words for "tryout":
   Gedankenexperiment, arrangement, attention, audience, audition,
   basic training, bench test, benefit, bill, briefing, bugging,
   clearing the decks, conference, debut, dry run, ear, eavesdropping,
   electronic surveillance, entertainment, equipment, exhibit,
   exhibition, familiarization, farewell performance,
   favorable attention, fixing, flesh show, flight test, foundation,
   groundwork, hearing, interview, listening, listening in, makeready,
   making ready, manufacture, mobilization, performance, pilot plan,
   planning, practical test, practice, prearrangement, preliminaries,
   preliminary, preliminary act, preliminary step, premiere, prep,
   preparation, preparatory study, preparing, prepping, prerequisite,
   presentation, presentment, pretreatment, processing, production,
   propaedeutic, provision, readying, rehearsal, road test, shakedown,
   shakedown cruise, show, spadework, stage presentation, swan song,
   test flight, test run, theatrical performance, training, treatment,
   trial, trial run, warm-up, wiretapping, workout