Foolish vs Idiotic

When to use each in English, with meaning, register, and examples.

Foolish

Top 2,000 (common)

Idiotic

InformalTop 5,000 (fairly common)
Most formal: FoolishMost common: Foolish
 FoolishIdiotic
Pronunciation🇬🇧 //ˈfuːlɪʃ//🇺🇸 //ˈfuːlɪʃ//🇬🇧 //ɪdɪˈɒtɪk//🇺🇸 //ɪdɪˈɑtɪk//
MeaningNot smart or sensible; lacking good judgement.Very foolish or stupid.
ExampleIt was foolish to invest all his savings in that risky project.His decision to skip the exam was idiotic.
RegisterNeutralInformal
How commonTop 2,000 (common)Top 5,000 (fairly common)
Collocationsfoolish mistake, foolish behavior, foolish decision, foolish question, foolish ideaidiotic behavior, idiotic idea, idiotic remarks
Antonymswise, sensible, prudent, smartintelligent, sensible, wise
Common mistakesConfusing 'foolish' with 'silly' - 'foolish' implies a lack of wisdom while 'silly' is lighter., Using 'foolish' as a noun - it's strictly an adjective., Incorrectly spelling 'foolish' as 'foolosh'.Used in formal writing., Confused with 'idiot' as a noun., Misused to describe minor mistakes.
Usage notesUse 'foolish' in both formal and informal contexts when describing decisions or actions that lack wisdom. Avoid using it in serious or sensitive situations where it might offend the person involved.Use 'idiotic' to describe something extremely foolish or nonsensical. Avoid it in formal settings as it can be considered offensive.

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Foolish
Idiotic

Frequently asked questions: Foolish vs Idiotic

What's the difference between Foolish and Idiotic?

Foolish: Not smart or sensible; lacking good judgement. Idiotic: Very foolish or stupid.

Which is more formal: Foolish and Idiotic?

Foolish is the most formal of these.

Which is more common: Foolish and Idiotic?

Foolish is the most common in everyday English.

Can you show an example of each?

Foolish: It was foolish to invest all his savings in that risky project. Idiotic: His decision to skip the exam was idiotic.

Can I use Foolish and Idiotic interchangeably?

Not always. Foolish and Idiotic are related and overlap in some contexts, but they differ in register, how common they are, and usage, so swapping one for another can change the meaning or tone. Check the differences above before substituting.

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