playpens

英

美 [ˈpleɪˌpɛnz]

n.  (幼儿)玩耍护栏
playpen的复数

柯林斯词典

• （供婴儿或幼儿在里面玩的）游戏围栏
  Aplaypenis a small structure which is designed for a baby or young child to play safely in. It has bars or a net round the sides and is open at the top.