noun A person with poor judgment or little intelligence.
You were a fool to cross that busy road without looking.
noun A jester; a person whose role was to entertain a sovereign and the court (or lower personages).
noun A stock character typified by unintelligence, naïveté or lucklessness, usually as a form of comic relief; often used as a source of insight or pathos for the audience, as such characters are generally less bound by social expectations.
noun Someone who has been made a fool of or tricked; dupe.
noun Someone who derives pleasure from something specified.
noun An informal greeting akin to buddy, dude, or man.
noun A particular card in a tarot deck, representing a jester.