puerile

1. ADJ If you describe someone or something as puerile, you mean that they are silly and childish. 幼稚的[表不满]

Concert organizers branded the group's actions as puerile. 演唱会举办方谴责了该乐团的幼稚行为。

...puerile, schoolboy humour. ...幼稚的小男生幽默。