insane
ihn-SAYN
Insane (adj) means suffering from serious mental illness; not of sound mind. Example: “He was declared legally insane and unfit to stand trial.”
adj
1
Suffering from serious mental illness; not of sound mind.
"He was declared legally insane and unfit to stand trial."
"In the old novel, the doctor decided the patient was insane and sent him away."
"The play tells the story of a woman who is wrongly called insane."
2
Extremely foolish, reckless, or impractical.
"It would be insane to quit your job with no savings."
"Driving in that storm is insane."
"Trying to cross that busy road without looking would be insane."
3
(informal) Extremely impressive, intense, or extraordinary.
"The view from the summit was insane."
"The band's last song was insane, and the whole crowd went wild."
"That goal was absolutely insane, and everyone jumped out of their seats."
How to use insane
Learner’s notesIn plain EnglishMentally unwell, or (casually) crazy/reckless, or (slang) amazingly good or intense.
When to use it
The mental-illness sense is now considered outdated and stigmatizing in clinical contexts; the casual senses (reckless, amazing) are common in everyday speech.
Common pairings
legally insane
go insane
insane amount of
Vocabulary Flow
Build your vocabulary from words like insane.
Vocabulary Flow serves the next word, and the next — meaning, pronunciation and an example each time. Practice at your level, or learn English in your own language.
Start vocabulary practice
Word forms
- Comparative
- more insane, insaner
- Superlative
- most insane, insanest
Fill the gap
Can you complete this real example?
He was declared legally _____ and unfit to stand trial.
Etymology
From Latin insanus, "unsound in mind" — in- ("not") plus sanus ("sound, healthy").
Synonyms
View more →Antonyms
Related words
Rhymes for insane
See all rhymes for insane →Frequently asked questions
What does “insane” mean?
The word “insane” means suffering from serious mental illness; not of sound mind. In plain terms, mentally unwell, or (casually) crazy/reckless, or (slang) amazingly good or intense.
How do you pronounce “insane”?
“Insane” is pronounced ihn-SAYN (/ɪnˈseɪn/ in IPA).
How do you use “insane” in a sentence?
Here is “insane” used in a sentence: “He was declared legally insane and unfit to stand trial.”
What is another word for “insane”?
Words with a similar meaning to “insane” include 5150, bananas, barking, barking mad, buggish and buggy.
What is the opposite of “insane”?
The opposite of “insane” — its antonyms — are sane and sober.
What part of speech is “insane”?
“Insane” is an adjective.
Where does the word “insane” come from?
The word “insane” comes from Latin. From Latin insanus, "unsound in mind" — in- ("not") plus sanus ("sound, healthy").
Is “insane” a common word?
“Insane” is a fairly common word in modern English, usually learned at around the B1 level.
Is 'insane' still a medical term?
No. Modern medicine avoids 'insane' because it is vague and stigmatising, preferring specific diagnoses such as psychosis or a named mental illness. The word survives mainly in law, as in the insanity defence, and in casual speech where it loosely means wild, extreme, or hard to believe.
What is the difference between insane and crazy?
Both once described serious mental illness, and both are now seen as outdated and insensitive in that sense. In everyday use they overlap as informal words for something wild or absurd. 'Insane' tends to sound stronger and more extreme, while 'crazy' is milder and far more common in casual talk.
Is 'insane' an offensive word?
It can be. Applied to a real person's mental health, 'insane' is outdated and hurtful, so careful writers use precise clinical terms instead. Used loosely to mean 'unbelievable' — an insane goal, an insane price — it is harmless slang, but the two senses are worth keeping apart.
Featured in
Vocabulary lists that include insane:
