antagonism antagonism /ænˈtæɡəˌnɪzəm/

noun

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