a professional clown employed to entertain a king or nobleman in the Middle Ages
"The court fool entertained the duke by telling witty jokes and performing acrobatics during the royal feast."
A person with poor judgment or little intelligence.
"The manager fired that fool for making such a simple mistake on his first day."
In plain English: A fool is someone who acts stupidly and makes bad decisions without thinking them through first.
"Don't let that fool convince you to buy such an expensive car."
Usage: Use this noun to describe someone who makes repeated bad decisions rather than simply lacking intelligence, as it implies active foolishness instead of innate stupidity. Avoid using it interchangeably with "idiot" if you want to emphasize the behavioral aspect over a permanent mental state.
spend frivolously and unwisely
"Fritter away one's inheritance"
fool or hoax
"The immigrant was duped because he trusted everyone"
"You can't fool me!"
indulge in horseplay
"Enough horsing around--let's get back to work!"
"The bored children were fooling about"
To trick; to deceive
"The magician's assistant managed to fool the entire audience into thinking he had vanished."
Foolish.
"It would be foolish to drive through the floodwaters without a boat."
The word "fool" comes from the Old French fol, which originally meant "mad," before entering Middle English as fole. It eventually replaced the native Old English term dwæs to describe a person who is silly or gullible.