Definitions of crazy:

• noun:   someone deranged and possibly dangerous
• adjective:   marked by foolish or unreasoning fondness

  Example: "She was crazy about him"

• adjective:   foolish; totally unsound

  Example: "A crazy scheme"

• adjective:   intensely enthusiastic about or preoccupied with

  Example: "Crazy about cars and racing"

• adjective:   possessed by inordinate excitement

  Example: "The crowd went crazy"

• adjective:   bizarre or fantastic

  Example: "Had a crazy dream"

• adjective:   affected with madness or insanity