Foolish | Definition of foolish by Merriam-Webster

Full Definition of FOOLISH

1

: lacking in sense, judgment, or discretion

2

a : absurd, ridiculous

b : marked by a loss of composure : nonplussed

3

: insignificant, trifling

— fool·ish·ly adverb

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First Known Use of FOOLISH

13th century

Related to FOOLISH

Synonyms: absurd, asinine, balmy, brainless, bubbleheaded, cockeyed, crackpot, crazy, cuckoo, daffy, daft, dippy, dotty, fatuous, featherheaded, fool, half-baked, harebrained, half-witted, inept, insane, jerky, kooky (also kookie), loony (also looney), lunatic, lunkheaded, mad, nonsensical, nutty, preposterous, sappy, screwball, senseless, silly, simpleminded, stupid, tomfool, unwise, wacky (also whacky), weak-minded, witless, zany, out to lunch

Antonyms: judicious, prudent, sagacious, sage, sane, sapient, sensible, sound, wise

Synonym Discussion of FOOLISH

simple, foolish, silly, fatuous, asinine mean actually or apparently deficient in intelligence. simple implies a degree of intelligence inadequate to cope with anything complex or involving mental effort <considered people simple who had trouble with computers>. foolish implies the character of being or seeming unable to use judgment, discretion, or good sense <foolish stunts>. silly suggests failure to act as a rational being especially by ridiculous behavior <the silly antics of revelers>. fatuous implies foolishness, inanity, and disregard of reality <fatuous conspiracy theories>. asinine suggests utter and contemptible failure to use normal rationality or perception <an asinine plot>.