Search Result for "downtime": 
Wordnet 3.0

NOUN (1)

1. a period of time when something (as a machine or factory) is not operating (especially as a result of malfunctions); 



WordNet (r) 3.0 (2006):

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]