lunatic; insane.

extremely or senselessly foolish.

a lunatic.

adjective

ape , barmy , batty , berserk , bonkers * , cracked , crazed , cuckoo , daffy * , daft , delirious , demented , deranged , flaky , flipped out , insane , kooky , lunatic , mad , maniacal , mental * , nuts , nutty , out of one’s mind , out to lunch , psycho , screwball * , screwy * , silly , touched * , unbalanced , wacky , absurd , harebrained , idiotic , imbecilic , moronic , nonsensical , preposterous , softheaded , tomfool , unearthly , zany , brainsick , crazy , disordered , distraught , dotty , maniac , mentally ill , moonstruck , off , touched , unsound , wrong , foolish

noun

crazy , eccentric , lunatic