The meaning of crazy is not mentally sound Marked by thought or action that lacks reason How to use crazy in a sentence. Crazy (comparative crazier, superlative craziest) of unsound mind [from 17th c.] synonym quotations synonyms Insane his ideas were both frightening and crazy.
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. Crazy can also mean behaving in a strange way esp Because of stress, as if you are mentally ill: Definition of crazy adjective in oxford advanced american dictionary