guān bào sī chóu
官:公事。借助公事以泄私愤。
元 施惠《幽闺记 图形追捕》:“这狗骨头,我倒替你官报私仇!叫左右拿下去打!”
官报私仇作宾语、定语;指借机报复。
an official avenges himself by taking advantage of performing his duty
虥(おおやけ)のことで死怨を晴(は)らす