idiot

The word “idiot” means a foolish or stupid person, or someone who makes a very poor decision. In plain terms, a strongly informal, often insulting word for someone acting foolishly.

“Idiot” is pronounced IH-dee-uht (/ˈɪdiət/ in IPA).

Here is “idiot” used in a sentence: “Only an idiot would leave the front door unlocked all night.”

Words with a similar meaning to “idiot” include addle-brain, addlehead, addle pate, airhead, baboon and beanbrain.

The opposite of “idiot” — its antonyms — are genius and intelligent person.

“Idiot” is a noun.

The word “idiot” comes from Greek. From Greek idiotes, originally meaning an ordinary private citizen with no special skill or office, later narrowing to mean an ignorant or foolish person.

“Idiot” is a fairly common word in modern English, usually learned at around the B2 level.

Yes. "Idiot" is an insult that labels someone as foolish or stupid, and directing it at a person will usually cause offence. Between close friends it is sometimes used playfully ("you idiot!"), but tone and context carry all the weight, so it is best avoided in formal or professional settings.

Both words describe someone who acts stupidly, but "fool" tends to emphasise poor judgment or being easily deceived, while "idiot" is blunter and stresses a lack of intelligence or a very poor decision. "Fool" also sounds slightly more old-fashioned and appears in set phrases like "make a fool of yourself."

In everyday modern English the two are largely interchangeable insults for a foolish or stupid person. Neither word has any technical or medical meaning today, and both are considered rude when aimed at a real person.

It can, but only in clearly playful contexts between people who know each other well, as in "You idiot, you nearly gave me a heart attack!" Without that warmth of tone, the word reads as a straightforward insult, so it should never be used affectionately with strangers or in writing where tone is hard to judge.