掛鑰匙兒童 [挂钥－儿－]

Jyutping gwaa3 joek6 si4 ji4 tung4
Pinyin guà yào shi ér tóng

Definitions (Wiktionary)
  1. noun
    latchkey kid
    (syn.) 钥匙儿童, 鑰匙兒童