Antagonism

1. noun

   (biochemistry) interference in or inhibition of the physiological action of a chemical substance by another having a similar structure

2. noun

   the relation between opposing principles or forces or factors

   “the inherent antagonism of capitalism and socialism”

3. noun

   an actively expressed feeling of dislike and hostility

4. noun

   a state of deep-seated ill-will

   Similar: hostility, enmity