insane

[in-seyn]

adjective

1. (not in technical use as a medical diagnosis) not sane; not of sound mind; mentally deranged.

   Synonyms: irrational, foolish, maniacal, crazy, crazed, lunatic, demented

2. of, relating to, or characteristic of a person who is mentally deranged.

   a wild and insane look on her face.

3. Law.,  considered to be or to have been affected with insanity, and therefore lacking legal responsibility or legal capacity.

   The judge deemed him criminally insane on the basis of his delusions and hallucinations.

4. temporarily unable to think clearly.

   I think I'm going insane from all the noise outside.

5. utterly senseless.

   an insane plan.

6. Slang.,  excessive or extravagant; extreme.

   This much snow in April is just insane!

7. Slang.,  astonishingly great; wonderful.

   Without his insane performance, the film would've been a total flop.

insane

/ ɪnˈseɪn /

adjective

1. 1. mentally deranged; crazy; of unsound mind

   2. ( as collective noun; preceded by the )

      the insane

2. characteristic of a person of unsound mind

   an insane stare

3. irresponsible; very foolish; stupid

Other Word Forms

• insanely adverb
• insaneness noun
• pseudoinsane adjective

Word History and Origins

Origin of insane¹

First recorded in 1550–60; from Latin insānus “unsound (of mind), demented, frenzied”; in- ³, sane

Synonym Study

See mad.

Example Sentences

"The press intrusion was insane, there was all sorts of dark stuff going on," said Church, who joins the line-up on BBC One's Celebrity Traitors this Wednesday.

From BBC

“The police out there and the amount of the security presence was insane,” McIlroy said.

From Los Angeles Times

Reflecting on the "insane" crowds at Twickenham, Muir opted for an unusual cultural reference.

From BBC

But she felt she had no choice: "Being able to afford running a home, it's just insane," she says.

From BBC

Lee's lawyers argued that she was insane at the time of the killing, which happened months after her husband died of cancer.

From BBC

Related Words

• crazy 
• delirious 
• demented 
• deranged 
• frantic 
• frenzied 
• kooky 
• nutty