animosity
n.a strong feeling of dislike or anger toward someone. It usually happens because of a past argument or a long history of not getting along.
n.a state of strong hostility or active ill will. Often implies a long-standing or deep-seated resentment between parties.
“There is no animosity between the two former rivals.”
“The long legal battle created a great deal of animosity between the two families, making any future reconciliation unlikely.”
“Despite their professional disagreements, the researchers maintained a civil relationship, ensuring that personal animosity did not cloud the objective evaluation of their shared data.”
Uncountable when referring to the general feeling; countable when referring to specific instances or acts of hostility.
“Increasingly, there is animosity from fans if a player leaves for a rival side.”
“Acrimony, anger and animosity: the Julian Alvarez summer transfer saga in a nutshell.”
From French animosité, from Latin animositas (“courage, spirit, vehemence”), from animosus, from animus (“courage, spirit, mind”); see animose, animate.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.