The meaning of crazy is not mentally sound There are 17 meanings listed in oed's entry for the adjective crazy, two of which are labelled obsolete, and one of which is considered offensive Marked by thought or action that lacks reason
Crazy jam jam booty : crazyjamjampics2
How to use crazy in a sentence.
Crazy adjective (interested) [ after noun ] used for saying that someone thinks about something all the time or wants it very much, in a way that some people might think is extreme:
One who is or appears to be mentally deranged To them she is not a brusque crazy, but 'appropriately passionate' (mary mcgrory). If you describe someone or something as crazy, you think they are very foolish or strange. When she gets on the motorcycle she goes crazy
Quotations he went crazy when he won.