latchkey /ˈlætʃˌkiː/ (also latch-key)

• 1. 

  ADJ If you refer to a child as a latchkey kid, you disapprove of the fact that they have to let themselves into their home when returning from school because their parents are out at work. 挂钥匙的; 形容儿童因父母都是上班族放学回家后不得不自行开门 [ADJ n] [表不满]