downtime

downtime
    n 1: a period of time when something (as a machine or factory)
         is not operating (especially as a result of malfunctions)
         [ant: {uptime}]
    

44 Moby Thesaurus words for "downtime":
      break, breath, breather, breathing place, breathing space,
      breathing spell, breathing time, cigarette break, cocktail hour,
      coffee break, 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,
      quiet spell, recess, relief, respite, rest, resting point, spell,
      stay, surcease, suspension, tea break, time off, time out,
      vacation