WordNet (r) 3.0 (2006):

time out
    n 1: a pause from doing something (as work); "we took a
         10-minute break"; "he took time out to recuperate" [syn:
         respite, recess, break, time out]

Moby Thesaurus II by Grady Ward, 1.0:

56 Moby Thesaurus words for "time out":
   break, breath, breather, breathing place, breathing space,
   breathing spell, breathing time, check in, check off, check out,
   cigarette break, clock in, clock out, cocktail hour, coffee break,
   downtime, enforced respite, half time, half-time intermission,
   halt, happy hour, holiday, interim, interlude, intermezzo,
   intermission, intermittence, interregnum, interruption, interval,
   letup, lull, off-time, pause, plateau, point of repose, punch in,
   punch out, punch the clock, quiet spell, recess, relief, respite,
   rest, resting point, ring in, ring out, sign out, spell, stay,
   surcease, suspension, tea break, time in, time off, vacation