|1.||openly expressed and usually mutual opposition|
|2.||the inhibiting or nullifying action of one substance or organism on another|
|3.||physiol the normal opposition between certain muscles|
|4.||biology the inhibition or interference of growth of one kind of organism by another|
antagonism an·tag·o·nism (ān-tāg'ə-nĭz'əm)
Mutual opposition in action between structures, agents, diseases, or physiological processes. Also called mutual resistance.