Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “crazy”

crazy

adjective  /ˈkreɪ·zi/ us  
very strange or foolish: She’s the craziest person I’ve ever met. [+ to infinitive] You’re crazy to rent the place without seeing it first. Crazy can mean mentally ill. Crazy can also mean behaving in a strange way esp. because of stress, as if you are mentally ill: The constant whine of the machine nearly drove (= made) me crazy. I think she’ll go (= become) crazy if she doesn’t take a vacation soon.
crazily
adverb [not gradable]  /ˈkreɪ·zə·li/ us  
craziness
noun [U]  /ˈkreɪ·zi·nəs/ us  

crazy

noun [C usually pl]  /ˈkreɪ·zi/ infml us  
a person who acts in a strange or threatening way, esp. one who is mentally ill: Are we talking about a bunch of crazies or about a legitimate military force?
(Definition of crazy from the Cambridge Academic Content Dictionary © Cambridge University Press)
What is the pronunciation of crazy?
Browse related topics

You are looking at an entry to do with Of unsound mind, but you might be interested in these topics from the Psychology, psychiatry, & psychoanalysis topic area:

Add Cambridge dictionaries to your browser to your website

“crazy” in American English

Definitions of “crazy” in other dictionaries

Word of the Day

debut

the occasion when someone performs or presents something to the public for the first time

Word of the Day

Come on – you can do it! Phrasal verbs with ‘come’.

by Liz Walter​,
November 19, 2014
As part of an occasional series on the tricky subject of phrasal verbs, this blog looks at ones formed with the verb ‘come’. If you are reading this blog, I’m sure you already know come from, as it is one of the first things you learn in class: I come from Scotland/Spain.

Read More 

ped-text verb

November 24, 2014
to text someone while walking I’m ped-texting, I’m looking down at my phone, 75 percent of the time.

Read More