What does foolish mean?
'Foolish' is an adjective denoting a lack of good sense, judgment, or prudence. A foolish act is one that a reasonable person would recognize as unwise — whether through carelessness, gullibility, impulsiveness, or simple failure to think things through. The word applies both to actions and to the people who take them: we call a decision foolish, and by extension describe its maker as behaving foolishly. A secondary sense covers embarrassment or absurdity, as when someone says they 'felt foolish' after a social misstep. Connotations range from gently teasing to openly critical, making it a flexible term in casual conversation and formal writing alike. Its lineage runs deep: it derives from 'fool', the word for the court jester of medieval Europe, whose sanctioned silliness gave us not just this adjective but the noun 'folly'. Common synonyms include 'silly', 'unwise', and 'senseless'; its natural opposites are 'wise', 'sensible', and 'prudent'.
adjectiveLacking good sense or judgment; unwise. Also, exhibiting or resulting from a lack of sense, as in foolish behavior or remarks.
- Showing a lack of good sense or judgment; unwise.
- Embarrassing or ridiculous; deserving of ridicule (e.g., feeling or looking foolish).
"It would be foolish to ignore the warnings entirely."
"It was foolish of me to leave my passport at home."
"He felt foolish standing at the door in his dressing gown."
The word 'foolish' descends from the same root as 'folly' — the medieval court jester's title of 'fool' quietly lives on in one of English's most everyday criticisms.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of foolish
'Foolish' derives from 'fool', a Middle English borrowing from Old French 'fol' (modern French 'fou'), itself descended from Latin 'follis', meaning a pair of bellows or a windbag — hence the ancient association of fools with empty-headedness. The adjective arose in Middle English as 'folissh' and has remained in continuous use since. Cognate terms include the noun 'folly', which came to denote both foolish conduct and, in architecture, costly impractical buildings.
Related word forms
How foolish is actually used
'Foolish' is a common, informal-to-neutral adjective used across everyday speech and writing. It often carries a mildly critical connotation, though it can be applied affectionately to one's own lapses in judgment ('I felt foolish'). The related phrase 'penny wise and pound foolish' is an established idiomatic usage describing someone careful with small sums but wasteful with large ones.
Easily confused with foolish
'Childish' describes immaturity typical of children, while 'foolish' describes a lack of good sense or judgment.