Rancor is a bitter and long lasting hatred.
An example of rancor is how Lex Luthor feels about Superman.
a continuing and bitter hate or ill will; deep spite or malice
Brit. sp. ran′cour
Origin of rancorMiddle English rancour ; from Old French rancor ; from LL, rankness, in LL(Ec), rancor ; from Classical Latin rancere, to be rank
Bitter, long-lasting resentment; deep-seated ill will: He was filled with rancor after losing his job.
Origin of rancorMiddle English, from Old French, from Late Latin, rancid smell, from Latin rancēre, to stink, be rotten.