プログレッシブ和英中辞典(第4版)の解説
しえん【私×怨】
personal enmity ((toward(s)));a (private) grudge ((against a person))
私怨から同僚を傷付けた
He injured his colleague out of personal enmity.
私怨を晴らす
satisfy [work off] a grudge/《文》 avenge a grievance
彼に私怨を抱いている
She has a grudge against him.