Collins COBUILD Advanced Learner's English Dictionary - foolish

1. If someone’s behaviour or action is foolish, it is not sensible and shows a lack of good judgment. It would be foolish to raise hopes unnecessarily... It is foolish to risk skin cancer. ADJ: oft it v-link ADJ to-inf • foolishly He admitted that he had acted foolishly. ADV: usu ADV with v • foolishness They don’t accept any foolishness when it comes to spending money. N-UNCOUNT 2. If you look or feel foolish, you look or feel so silly or ridiculous that people are likely to laugh at you. I didn’t want him to look foolish and be laughed at. = ridiculous ADJ: usu v-link ADJ • foolishly He saw me standing there, grinning foolishly at him. ADV: ADV after v