Antagonism (3,4)
There are a few possibilities for this:
ill will
(Other definitions for animus that I've seen before include "spirit of hostility" , "Motivating spirit" , "Hostile feeling" , "Hostile spirit in speech or action" , "Feeling of strong dislike" .)
'antagonism' is the definition.
(I know that antagonism can be written as enmity)
This is the entire clue.
(Other definitions for enmity that I've seen before include "discord" , "Hatred, hostility" , "Personal hostility" , "Animus" , "Hostility, ill-will" .)
(Other definitions for ill will that I've seen before include "Enmity" , "Hostile and unkind feeling" , "Hostility, unkind feeling" , "Disposition of enemy" , "Bitterness" .)