an argument that has existed for a long time between two people or groups, causing a lot of anger or violence

a family feud 家族世仇

a ten-year-old feud between the two countries 两国间长达10年的不和

a bitter feud over land 土地引起的激烈的长期争执

to have a feud with someone

They've been feuding with their neighbours for years over a boundary issue. 多年来，他们一直为了地界问题与邻居不和。