rat on
US /ræt ɑːn/
UK /ræt ɑːn/

1.
donosić na, kablować na
to inform on someone, especially to an authority
:
•
He threatened to rat on his friends if they didn't help him.
Groził, że doniesie na swoich przyjaciół, jeśli mu nie pomogą.
•
She decided not to rat on her brother, even though he broke the rules.
Postanowiła nie donosić na brata, mimo że złamał zasady.