Antagonism

{{wiktionary|antagonism}}

Antagonism may refer to:

• The characteristic of an antagonist
• Antagonism (chemistry), where the involvement of multiple agents reduces their overall effect
• Drug antagonism, a drug that stops the action or effect of another substance, preventing a biological response
• Receptor antagonism or pharmacological antagonism, the action of a drug that inhibits the function of an agonist at the level of a receptor
• Antagonism (phytopathology), an effect that suppresses the activity of a plant pathogen
• Reflexive antagonism of muscles
• Intraspecific antagonism, disharmonious or antagonistic interaction between two individuals of the same species