foolfoolfools1nouna person who is silly or who does something silly: You fool! You forgot to lock the door!make a fool of yourselfto do something that makes you look silly in front of other people: He always makes a fool of himself at parties.foolfoolfoolsfooledfooling2verb (fools, fooling, fooled)to make somebody believe something that is not truesame meaningtrick: You can't fool me! I know you're lying! fool about, fool aroundto do silly things: Stop fooling about with that knife.