1 crazy /ˈkreɪzi/ adjective
crazier; craziest
1 crazy
crazier; craziest
Learner's definition of CRAZY
[also more crazy; most crazy]
: not sane: such as
usually offensive : having or showing severe mental illness
◊ This sense is no longer used in a serious way and is now usually considered offensive. The phrase mentally ill is preferred.
: unable to think in a clear or sensible way
used in the phrase drive/make (someone) crazy to describe annoying or bothering someone very much
see also stir-crazy
: wild and uncontrolled
: very foolish or unreasonable
: very strange or unusual
: liking someone or something very much : very fond of or enthusiastic about someone or something
often + about

go crazy

: to become mentally ill : to go insane
usually used in an exaggerated way
: to act in a way that is out of control : to act wildly

like crazy

: with a lot of energy and speed
: very quickly
: very much

— craziness

noun [noncount]
2 crazy /ˈkreɪzi/ noun
plural crazies
2 crazy
plural crazies
Learner's definition of CRAZY
[count] chiefly US, informal
: a person who is crazy
3 crazy /ˈkreɪzi/ adverb
3 crazy
Learner's definition of CRAZY
US, informal
: very or extremely