childish

US /ˈtʃaɪl.dɪʃ/
UK /ˈtʃaɪl.dɪʃ/
"childish" picture
1.

子供っぽい, 幼稚な

of, like, or appropriate to a child

:
She has a very childish handwriting.
彼女はとても子供っぽい字を書く。
His behavior was quite childish for his age.
彼の行動は年齢の割にはかなり子供っぽいものだった。