Synonyms of lunatic in English:

lunatic


See definition of lunatic

noun

1‘a dangerous lunatic’

SYNONYMS
maniac, madman, madwoman, psychopath, psychotic
informal loony, loon, nut, nutter, nutcase, nutjob, cuckoo, head case, headbanger, screwball, psycho
Scottish informal radge
US informal wing nut
informal have a screw loose, have bats in one's belfry, have bats in the belfry

2‘when I'm in a bad mood I drive like a lunatic’

SYNONYMS
fool, idiot, imbecile, moron

adjective

1‘a lunatic prisoner’

SYNONYMS
mad, insane, mentally ill, certifiable, deranged, demented, of unsound mind, out of one's mind, not in one's right mind, sick in the head, not together, crazy, crazed, non compos mentis, unbalanced, unhinged, unstable, disturbed, distracted, stark mad, manic, frenzied, raving, distraught, frantic, hysterical, delirious, psychotic, psychopathic, mad as a hatter, mad as a March hare, away with the fairies, foaming at the mouth
British sectionable
informal mental, off one's head, out of one's head, off one's nut, nuts, nutty, nutty as a fruitcake, off one's rocker, not right in the head, not quite right in the head, round the bend, stark raving mad, stark staring mad, raving mad, bats, batty, bonkers, dotty, cuckoo, cracked, loopy, loony, bananas, loco, dippy, screwy, schizoid, touched, gaga, up the pole, off the wall, not all there, not right upstairs
British informal barmy, crackers, barking, barking mad, round the twist, off one's trolley, as daft as a brush, not the full shilling
North American informal buggy, nutsy, nutso
out of one's tree, meshuga, squirrelly, wacko
Canadian, Australian, New Zealand informal bushed
Australian informal yarra
New Zealand informal porangi
Australian informal have kangaroos in one's top paddock, have kangaroos in the top paddock
ANTONYMS

sane

2‘a lunatic idea’

SYNONYMS
foolish, stupid, silly, idiotic, half-witted, witless, brainless, mindless, thoughtless, imprudent, incautious, irresponsible, injudicious, indiscreet, unwise, unintelligent, unreasonable
ill-advised, ill-considered, impolitic, rash, reckless, foolhardy, lunatic
absurd, senseless, pointless, nonsensical, inane, fatuous, ridiculous, laughable, risible, derisible
informal dumb, dim, dim-witted, dopey, gormless, damfool, half-baked, hare-brained, crackbrained, pea-brained, wooden-headed, thickheaded, nutty, mad, crazy, dotty, batty, dippy, cuckoo, screwy, wacky
British informal barmy, daft
Scottish, Northern English informal glaikit
North American informal dumb-ass, chowderheaded
West Indian informal dotish
ANTONYMS

sensible, wise