Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “rat on sb/sth”

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.
(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

Translations of “rat on sb/sth”

Word of the Day

give the green light to sth

to give permission for someone to do something or for something to happen

Word of the Day

Highly delighted, bitterly disappointed, ridiculously cheap: adverbs for emphasis.

by Liz Walter,
October 22, 2014
We often make adjectives stronger by putting an adverb in front of them. The most common ones are very and, for a stronger meaning, extremely: He was very pleased. The ship is extremely large. However, we don’t use very or extremely for adjectives that already have a strong meaning, for example fantastic,

Read More 

life tracking noun

October 20, 2014
the use of one or more devices or apps to monitor health, exercise, how time is spent, etc.

Read More