round on
US /raʊnd ɑːn/
UK /raʊnd ɑːn/

1.
scagliarsi contro, attaccare
to turn on someone suddenly and attack them, either verbally or physically
:
•
She suddenly rounded on him, accusing him of lying.
Improvvisamente gli si scagliò contro, accusandolo di mentire.
•
The crowd rounded on the speaker after his controversial remarks.
La folla si scagliò contro l'oratore dopo le sue osservazioni controverse.