en foutre une

IPA(Pronunciation)

transitive with à

（àを伴う他動詞）（俗語、省略）殴り倒す

English Meaning

(transitive with à) (vulgar, by ellipsis) to beat the crap out of

Le patron a menacé le voleur en criant : 'Si tu reviens ici, je vais t'en foutre une!'

上司は泥棒に向かって、『ここに戻ってくるなら、容赦なくぶっ飛ばすぞ！』と叫んだ.

The boss threatened the thief, shouting: 'If you come back here, I'm going to beat the crap out of you!'