crazy

If someone is crazy, they do not think or act normally. A crazy person might do very strange thing or believe things that everyone knows are not true.

Example: I knew he was crazy when he said he was Jesus Christ.

If someone is crazy, they are fun, because no one can guess what they might do next.

Example: I love her because she is so wild and crazy.

To be crazy about someone or something means to like someone or something very much.

Example: I'm crazy about basketball.

If something is crazy, it is very strange, not what a person would expect.

Example: The weather has been crazy, with snow in summer and hot day in winter.

A crazy is person who is crazy (see above). Usually this is for a person who is insane.