down·time /ˈdaʊntaɪm/ noun [uncountableU] 1. TDthe time when a computer is not working 〔计算机的〕停机时间
2 (also down time) informal a period of time when you have finished what you were doing, and you can relax or do something that you had not originally planned to do 〔完成工作后的〕自由支配时间 Often, during semesters, you have down time when you can do some exercise. 学期当中常常会有可供自由支配的时间来进行锻炼。
—downtime adjectiveadj downtime activities for teachers 教师的自由活动