definition: a fight planned or carried out in order to settle a persistent feeling of resentment, esp. one due to some cause, such as an insult or injury
grudge: c.1450, from Old French grouchier to grumble, probably of Germanic origin; compare Old High German grunnizon to grunt
fight: Old English feohtan; related to Old Frisian fiuchta, Old Saxon, Old High German fehtan to fight)
Both of them have been feuding for a long time, grudge fights between them are frequent.
Edwin Goh Duo Yao, 1-2