insane
89 synonyms and 2 antonyms for insane, grouped by meaning and by how common each one is.
Adj — Suffering from serious mental illness; not of sound mind.
Synonyms
Everyday swaps
Common words most readers know — safe in any writing.
Less common
Still standard English, but they carry more weight.
Rare, literary or technical
Precise, but they will stand out — check the sense before using one.
Antonyms
How to use insane
The word patterns that sound natural to a native speaker.
The mental-illness sense is now considered outdated and stigmatizing in clinical contexts; the casual senses (reckless, amazing) are common in everyday speech.
Etymology
From Latin insanus, "unsound in mind" — in- ("not") plus sanus ("sound, healthy").
Full origin of 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Both once described serious mental illness, and both are now seen as outdated and insensitive in that sense.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.