Preposterous, ludicrous, laughable, idiotic, foolish, inane, insane, unreasonable, illogical, pointless, outrageous, astonishing, fantastic, grotesque, incredible, implausible, barmy, ridiculous, farcical, risible, stupid, silly, imbecilic, hare-brained, irrational, nonsensical, senseless, shocking, monstrous, incongruous, unbelievable, unthinkable, crazy, and daft.