[also more crazy; most crazy] 1 : not sane: such as a usually offensive : having or showing severe mental illness
▪ a hospital for crazy people ◊This sense is no longer used in a serious way and is now usually considered offensive. The phrase mentally ill is preferred.
b : unable to think in a clear or sensible way
▪ She's crazy with jealousy. ▪ He's been acting kind of crazy lately.
c — used in the phrase drive/make (someone) crazy to describe annoying or bothering someone very much ▪ It makes me crazy [=I feel very annoyed] when people drive like that. ▪ That noise is driving me crazy. [=it is really annoying me] ▪ The kids were driving the teacher crazy. — see also stir-crazy 2 : wild and uncontrolled
▪ He had a crazy [=crazed, insane, wild] look in his eyes. 3 : very foolish or unreasonable
▪ He likes to drive at crazy [=insane] speeds. ▪ There are a lot of crazy drivers on the streets. ▪ You are crazy to have paid so much for this car. ▪ You would be crazy not to accept their offer! ▪ What a crazy thing to do! 4 : very strange or unusual
▪ She likes crazy hair colors, like pink and blue. ▪ How do you think of all these crazy ideas? ▪ I love to listen to my uncle's crazy stories about his job. 5 : liking someone or something very much : very fond of or enthusiastic about someone or something
▪ She's crazy for anything having to do with Japanese animation. ▪ teenagers who are girl/boy crazy [=very interested in girls/boys] — often + about ▪ They are crazy about each other. [=they like each other a lot] ▪ He wasn't crazy about making the trip, but was glad he did in the end. ▪ She is crazy about baseball.