The meaning of crazy is not mentally sound :. Abnormal absurd anamorphous ape apish arrested asinine askew asymmetric avid babbling backward balmy bananas barmy bats batty befooled beguiled bent bereft of reason.
Meaning full of cracks or flaws is from 1580s;. Crazy is a term with a rich tapestry of meanings, from describing mental states to expressing intense enthusiasm or surprise.