foolish

foolish — adjective

1. behaving or speaking in a way that shows you have not thought carefully about th

1.adjectiveB1
Definition

behaving or speaking in a way that shows you have not thought carefully about the likely results of your actions, often causing problems or a feeling of embarrassment afterwards

Example

Tanvi felt foolish after she locked her keys inside the car.

feel + foolish (predicative after linking verb)

It was foolish of Hao to quit his job before he found a new one.

it + be + foolish of + someone + to-infinitive

Common collocations
  • foolish mistake
  • foolish decision
  • foolish thing
  • foolish question
  • foolish idea
  • feel foolish
  • look foolish
  • make someone look foolish
Synonyms
  • stupid

    stronger and more likely to cause offence when directed at a person; implies low intelligence rather than a single unwise action

  • silly

    less serious and more playful; often used for harmless or childish mistakes

  • unwise

    more formal and less emotional; focuses on poor judgment in a specific decision

  • absurd

    emphasises how unreasonable or ridiculous an idea or action is

Antonyms
  • wise

    having or showing good judgment based on experience and knowledge

  • sensible

    practical and level-headed; making decisions based on reason rather than emotion

  • prudent

    more formal; careful and cautious, especially about avoiding risks or future problems

Grammar Patterns

it + be + foolish + of [someone] + to-infinitive

feel / look / seem foolish

make a foolish + noun

Usage Note

Can be used both before a noun (a foolish decision) and after linking verbs such as feel, look, or seem. The pattern 'it is/was foolish of someone to do something' always takes the preposition 'of', never 'for'. Less offensive than 'stupid' when describing a person.

Common Mistakes

It was foolish for him to go alone.
It was foolish of him to go alone.
the correct preposition after 'foolish' when describing someone's action is 'of', not 'for'.

Word family

Synonym discussion

Sense: adjective/1

All four words describe a lack of good judgment, but they differ in strength and tone. 'Foolish' is the most neutral and versatile — you can use it about your own actions or someone else's without sounding harsh ('It was foolish of me to forget the meeting'). 'Stupid' is much stronger and can feel insulting when directed at a person; it implies a basic lack of intelligence rather than a single bad call. 'Silly' is the lightest of the group — it suits harmless, small-scale errors and often carries affection or humour ('What a silly thing to say!'). 'Unwise' sits at the formal end; it sounds measured and objective, making it a good choice for professional or written feedback ('an unwise investment strategy'). When in doubt about which word to use, 'foolish' is almost always safe.

foolish ↗stupid ↗silly ↗unwise ↗

Common collocations

Nouns

Adverbs

  • quite foolish
  • rather foolish
  • very foolish
  • a little foolish
  • extremely foolish

Phrases

  • it is foolish to...
  • feel foolish about...

Prepositions

  • foolish of

Etymology

LatinFrenchEnglish

Foolish comes from the word 'fool', which originally meant a person who lacks good sense or judgment. The ending '-ish' turns the noun into an adjective meaning 'having the qualities of a fool'. The word 'fool' itself traces back through Old French 'fol' (mad, insane, foolish) to the Latin word 'follis' (bellows or windbag) — a slang term Romans used for an empty-headed person, likening the mind to a bag full of nothing but air.