latchkey child n.
挂钥匙儿童
latchkey child[ noun ]
a school-age child who is home without adult supervision for part of the day (especially after school until a parent returns home from work)
<noun.person>
latchkey child \latch"key` child\, n.
A child who frequently spends part of the day at home without
adult supervision, especially a school child who returns home
before the parent(s) return from work. Called also {door-key
child}.
[PJC]