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

1.
冲着...发火, 围攻
to turn on someone suddenly and attack them, either verbally or physically
:
•
She suddenly rounded on him, accusing him of lying.
她突然冲着他发火,指责他撒谎。
•
The crowd rounded on the speaker after his controversial remarks.
在演讲者发表争议言论后,人群围攻了他。