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Definitions

insane

[in-seyn] / ɪnˈseɪn /
ADJECTIVE
mad
Synonyms
STRONGEST
crazy delirious demented deranged frantic frenzied kooky nutty
WEAK
aberrant bananas batty crazed cuckoo daft frenetic loony lunatic non compos mentis of unsound mind off one's rocker out of one's mind raving unbalanced unhinged unsound unstable
Antonyms
STRONGEST
balanced calm collected rational reasonable sane sensible wise
WEAK
OK sound unenthusiastic

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Grieving is also time to get angry and justified in your own insane behavior.

From Slate • Apr. 23, 2026

Kahl felt like an insider because she had randomly come across the insane deal while shopping on Google Flights the night before.

From The Wall Street Journal • Apr. 22, 2026

I remember when he told me about the membership, I was like, “You pay how much? That’s insane, dude.”

From Los Angeles Times • Apr. 17, 2026

Shipping costs are up, too, Ferreri said, describing "insane" prices for the delivery of essential farm equipment.

From Barron's • Apr. 11, 2026

This monster child stalked me for a month before I found a logic to banish her: that I was likely insane.

From "Educated" by Tara Westover

Vocabulary lists containing insane

salu, san (health)

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