noun

hostile behaviour; unfriendliness or opposition.

their hostility to all outsiders

antagonism,unfriendliness,bitterness,malevolence,malice,unkindness,spite,spitefulness,rancour,rancorousness,venom,wrath,anger,hatred,aggression,aggressiveness,belligerence,bellicosity,pugnaciousness,militancy,truculence,warlikeness,opposition,animosity,antipathy,animus,ill will,ill feeling,bad feeling,resentment,aversion,enmity,inimicalness