rat on
US /ræt ɑːn/
UK /ræt ɑːn/
1.
delatar, chivarse de
to inform on someone, especially to an authority
:
•
He threatened to rat on his friends if they didn't help him.
Amenazó con delatar a sus amigos si no lo ayudaban.
•
She decided not to rat on her brother, even though he broke the rules.
Decidió no delatar a su hermano, aunque él rompió las reglas.