1. fighting; acts of overt warfare
the outbreak of hostilities;
Synonyms : ['belligerency']

2. a hostile (very unfriendly) disposition
he could not conceal his hostility;
Synonyms : ['hostility', 'ill_will']

3. a state of deep-seated ill-will

Synonyms : ['hostility', 'enmity', 'antagonism']

4. the feeling of a hostile person
he could no longer contain his hostility;
Synonyms : ['hostility', 'enmity', 'ill_will']

5. violent action that is hostile and usually unprovoked

Synonyms : ['aggression', 'hostility']