Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “lunatic”

See all translations

lunatic

noun [C] uk   /ˈluː.nə.tɪk/ us    /-t̬ɪk/
someone who behaves in a silly or dangerous way: He drives like a lunatic. offensive old-fashioned a person who is mentally ill

lunatic

adjective uk   /ˈluː.nə.tɪk/ us    /-t̬ɪk/
silly in a dangerous way
Translations of “lunatic”
in Korean 미치광이…
in Arabic مَجْنون…
in Portuguese louco, -a, demente…
in Catalan boig, boja…
in Japanese 狂人…
in Italian folle, pazzo, -a…
in Chinese (Traditional) 瘋子,癲狂的人, 精神病人…
in Russian сумасшедший…
in Turkish deli, kaçık, fıttırık…
in Chinese (Simplified) 疯子,癫狂的人, 精神病人…
in Polish wariat/ka…
(Definition of lunatic from the Cambridge Advanced Learners Dictionary & Thesaurus © Cambridge University Press)
What is the pronunciation of lunatic?
Add Cambridge dictionaries to your browser to your website

Definitions of “lunatic” in other dictionaries

Word of the Day

piglet

a baby pig

Word of the Day

I won’t tolerate it! Replacing formal words with phrasal verbs.

by Liz Walter,
April 01, 2015
When you are using a language, it is important to understand if a word is formal or informal, so that you can use it in an appropriate way. You might hear people saying dosh for money, or spud for potato, but they wouldn’t write those words in a formal essay. Similarly, a

Read More 

stackin’ p

March 30, 2015
idiom slang earning a lot of money ‘That’s a very generous present.”Yeah, well, she’s stackin’ p, innit?’

Read More