noun
Refers to play or games typical of children; can also imply something trivial or easy.
大人にとっては子供遊びのように思えるかもしれない。
To an adult, it might seem like child's play.
彼は子供遊びに夢中になっている。
He is absorbed in children's games.
Compound of 子供 (child) and 遊び (play).