adj. 25B6; adjective
he was killed by his mad brother : INSANE, mentally ill, certifiable, deranged, demented, of unsound mind, out of one's mind, not in one's right mind, sick in the head, crazy, crazed, lunatic, non compos mentis, unhinged, disturbed, raving, psychotic, psychopathic, mad as a hatter, mad as a March hare, away with the fairies; informal mental, off one's head, off one's nut, nuts, nutty, off one's rocker, not right in the head, round the bend, stark staring/raving mad, bats, batty, bonkers, dotty, cuckoo, cracked, loopy, loony, doolally, bananas, loco, dippy, screwy, schizoid, touched, gaga, up the pole, not all there, not right upstairs; Brit. informal barmy, crackers, barking, barking mad, round the twist, off one's trolley, not the full shilling; N. Amer. informal nutso, out of one's tree, meshuga, wacko, gonzo; Austral./NZ informal bushed; NZ informal porangi; ( be mad ) informal have a screw loose, have bats in the/one's belfry; Austral. informal have kangaroos in the/one's top paddock; ( go mad ) lose one's reason, lose one's mind, take leave of one's senses; informal lose one's marbles, crack up.
(informal) I'm still mad at him : ANGRY, furious, infuriated, irate, raging, enraged, fuming, incensed, seeing red, beside oneself; informal livid, spare; informal, dated in a wax; Brit. informal aerated; N. Amer. informal sore; poetic/literary wrathful; ( go mad ) lose one's temper, get in a rage, rant and rave; informal explode, go off the deep end, go ape, flip, flip one's lid; Brit. informal do one's nut; N. Amer. informal flip one's wig.
some mad scheme : FOOLISH, insane, stupid, lunatic, foolhardy, idiotic, senseless, absurd, impractical, silly, inane, asinine, wild, unwise, imprudent; informal crazy, crackpot, crackbrained; Brit. informal daft.
(informal) he's mad about jazz : ENTHUSIASTIC, passionate; ardent, fervent, avid, fanatical; devoted to, infatuated with, in love with, hot for; informal crazy, dotty, nuts, wild, hooked on, gone on; Brit. informal potty; N. Amer. informal nutso.
it was a mad dash to get ready : FRENZIED, frantic, frenetic, feverish, hysterical, wild, hectic, manic.
sane, pleased, sensible, indifferent, calm.
25A0; like mad (informal)
I ran like mad : FAST, quickly, rapidly, speedily, hastily, hurriedly.
he had to fight like mad : ENERGETICALLY, enthusiastically, madly, furiously, with a will, for all one is worth, passionately, intensely, ardently, fervently; informal like crazy, hammer and tongs; Brit. informal like billy-o.