rat on

Idioms and Phrases

Betray a comrade by giving information, as in He ratted on his best friend to the police . [ Slang ; early 1900s]

Example Sentences

Yet he also refuses to identify someone who can prove his innocence because he does not rat on people, and, he insists, he is innocent of the killings.

From Salon

He is also loyal and refuses to rat on someone who can prove his innocence.

From Salon

In 2015, he says, he hurt himself while hiking in Glacier National Park, and subsequently told medical personnel about the old bullet lodged in his arm—requiring him to come up with a cover story to tell the ranger about how it got there because he still didn’t want to rat on the individuals he served with.

From Slate

In an interview in 2000, he remembered cornering a large rat on the staircase of his communal apartment block.

From BBC

Ella wouldn't rat on her friends.

From Literature

Related Words

• acknowledge
• assert
• blurt out
• concede
• confide
• declare
• disclose
• divulge
• profess
• prove
• recognize
• relate
• reveal