The meaning of CRAZY is not mentally sound : marked by thought or action that lacks reason : insane —not used technically. How to use crazy in a sentence.

Crazy can also mean behaving in a strange way esp. because of stress, as if you are mentally ill:

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.

Definition of crazy adjective in Oxford Advanced American Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more.

Caused by or arising from mental derangement; marked by or manifesting insanity: as, a crazy speech; crazy actions. from the GNU version of the Collaborative International Dictionary of English.

CRAZY definition: mentally deranged; demented; insane. See examples of crazy used in a sentence.