Antagonism - Definition

n 1: a state of deep-seated ill-will [syn: hostility,
enmity, antagonism]
2: the relation between opposing principles or forces or
factors; "the inherent antagonism of capitalism and
socialism"
3: an actively expressed feeling of dislike and hostility
4: (biochemistry) interference in or inhibition of the
physiological action of a chemical substance by another
having a similar structure