Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “rat on sb/sth”

See all translations

rat on sb/sth

verb uk phrasal verb with rat   /ræt/ slang disapproving us  
to not be loyal to someone, especially by giving away secret information about them, or to fail to do something that you said you would do: He ratted on us. They ratted on the deal.
Translations of “rat on sb/sth”
in Chinese (Traditional) 背叛, (尤指)告密出賣,對…背信棄義…
in Chinese (Simplified) 背叛, (尤指)告密出卖,对…背信弃义…
(Definition of rat on sb/sth from the Cambridge Advanced Learners Dictionary & Thesaurus © Cambridge University Press)
What is the pronunciation of rat on sb/sth?
Add Cambridge dictionaries to your browser to your website

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