Englishdaft
adjective British, informal
1 that's a daft idea:
absurd, preposterous, ridiculous, ludicrous, farcical, laughable, risible;
idiotic, stupid, foolish, foolhardy, unwise, imprudent, ill-conceived, silly, inane, puerile, infantile, fatuous, imbecilic, harebrained, half-baked;
unreasonable, irrational, illogical, nonsensical, pointless, senseless, impracticable, unworkable, unrealistic;
peculiar, odd, strange, queer, weird, eccentric, bizarre, fantastic, incongruous, grotesque;
informal crazy, cock-eyed;
British, informal barmy, potty.
▷antonyms sensible.
2 are you daft or something?:
simpleminded, simple, stupid, idiotic, moronic, imbecilic, dull-witted, dull, dimwitted, slow-witted, slow, witless, halfwitted, feebleminded, dunce-like, cretinous, empty-headed, vacuous, vapid;
deranged, unhinged, insane, mad;
informal touched, thick, dim, dopey, dumb, dozy, birdbrained, peabrained, pig-ignorant, bovine, slow on the uptake, soft in the head, brain-dead, boneheaded, lamebrained, chuckleheaded, dunderheaded, wooden-headed, fat-headed, muttonheaded, not all there, not quite right, crazy, mental, nuts, nutty, cracked, cuckoo, bonkers, dippy;
British, informal not the full shilling, dotty, potty, batty, crackers, barmy, thick as two short planks;
North American, informal dumb-ass.