Antagonism

n. hostility; conflict

Antagonism is hostility that results in active resistance, opposition, or contentiousness. Additionally, it may refer to:Antagonism (chemistry), where the involvement of multiple agents reduce their overall effect Antagonism (philosophy), a principle, force or factor that is an active resistance, opposition, or contentiousnessAntagonism (pharmacology), when a substance binds to the same site an agonist would bind to without causing activation of the receptorAntagonism (phytopathology), the action of any microbes that suppresses the activity of a plant pathogen.
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Antagonism /an·tag·o·nism/ opposition or contrariety between similar things, as between muscles, medicines, or organisms; cf. antibiosis. [more]Antagonism - Community and Resources

Noun
1. a state of deep-seated ill-will
(synonym) hostility, enmity
(hypernym) state
(hyponym) latent hostility, tension
(derivation) antagonize, antagonise
2. the relation between opposing principles or forces or factors; "the inherent antagonism of capitalism and socialism"
(hypernym) opposition, oppositeness
(derivation) antagonize, antagonise, counteract
3. an actively expressed feeling of dislike and hostility
(hypernym) hostility, enmity, ill will
(derivation) antagonize, antagonise
4. (biochemistry) interference in or inhibition of the physiological action of a chemical substance by another having a similar structure
(hypernym) hindrance, interference
(classification) biochemistry

(n.)
Opposition of action; counteraction or contrariety of things or principles.