[adjective]Foolish means unwise, ridiculous or lacking in judgment.That was an extremely foolish thing to have done.She was afraid that she would look foolish if she refused.It was foolish of them to hope that he would change his ways.You were foolish to trust a man like Mick.
FOOLISH
Meaning of FOOLISH in English
Cambridge English vocab. Кембриджский английский словарь. 2012