Synonyms of insane in English:

insane


See definition of insane

adjective

1‘she was examined by three doctors and declared insane’

SYNONYMS
mentally ill, severely mentally disordered, of unsound mind, certifiable, psychotic, schizophrenic
mad, mad as a hatter, mad as a March hare, deranged, demented, out of one's mind, out of one's head, not in one's right mind, sick in the head, unhinged, unbalanced, unstable, disturbed, crazed, crazy, hysterical
non compos mentis
British sectionable
informal raving mad, stark raving mad, stark staring mad, away with the fairies, not all there, bonkers, cracked, batty, bats, cuckoo, loony, loopy, nuts, nutty, nutty as a fruitcake, screwy, bananas, off one's rocker, off one's head, off one's chump, off one's nut, off the wall, round the bend
British informal crackers, barmy, barking, barking mad, off one's trolley, round the twist, as daft as a brush, not the full shilling
North American informal buggy, nutsy, nutso, out of one's tree, wacko, squirrelly
Canadian, Australian, New Zealand informal bushed
New Zealand informal porangi
ANTONYMS

sane

2‘he made an insane suggestion’

SYNONYMS
extremely foolish, idiotic, stupid, silly, senseless, nonsensical, pointless, absurd, ridiculous, ludicrous, farcical, laughable, preposterous, weird, bizarre, fatuous, inane, imbecilic, moronic, asinine, mindless, hare-brained, half-baked, ill-conceived
impracticable, untenable, implausible, unreasonable, irrational, illogical, unrealistic, unthinkable
informal potty, crazy, mad, off beam, way out, full of holes, cock-eyed
British informal daft, barmy
ANTONYMS

sensible

3‘the fly's buzzing had been driving me insane’

SYNONYMS
mad, crazy
angry, annoyed, irritated, cross, vexed, exasperated, incensed, enraged
informal aggravated, hot under the collar, foaming at the mouth
British informal spare, crackers
ANTONYMS

calm