feud       
 noun [ C ] uk/fjuːd/ us/fjuːd/
 夙怨;世仇;长期争斗
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 
 feud       
verb [ I ] uk/fjuːd/ us/fjuːd/
 (与…)长期斗争;结世仇
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。