馬ば鹿かなことをする

expression, suru verb (irregular)

do a stupid thing; do something foolish

A common phrase for acting foolishly or making a silly mistake. Often used in self-reproach or to criticize someone's action.

• また馬ば鹿かなことをしてしまった。

  I did something stupid again.

• 彼かれはよく馬ば鹿かなことをする。

  He often does foolish things.