detention
/dɪˈtenʃən/noun
mass noun
1- the action of detaining someone or the state of being detained in official custody, especially as a political prisoner（尤指政治犯的）拘留：
he committed suicide while in police detention.
他在被警方拘留期间自杀。
1.1
- the punishment of being kept in school after hours（作为一种处罚的）课后留校：
teachers were divided as to the effectiveness of detention
教师们对于课后留校的效果意见不一
count noun masters gave lines or detentions.老师不是罚抄写就是罚留校。
词源
late Middle English （in the sense 'withholding of what is claimed or due'）： from late Latin detentio（n-）， from Latin detinere 'hold back' （see DETAIN）.