Synonym for hostile is "antagonistic"

aggressive [adjective]

means "combative"
warlike, bellicose, hostile, militant, belligerent, offensive

alien [adjective]

means "opposite"
adverse, hostile, opposed, extraneous, unconnected, unfriendly

antipathetic [adjective]

means "unpleasant"
abhorrent, loathsome, hostile, unfriendly, repugnant, invidious

antisocial [adjective]

means "asocial"
unfriendly, hostile, misanthropic, unsociable, cynical

averse [adjective]

means "disinclined"
hostile, unwilling, reluctant, loath, opposed, inimical

bitter [adjective]

means "behaviour"
embittered, ill-natured, resentful, antagonistic, rancorous, hostile

cold [adjective]

means "behaviour"
unfriendly, heartless, glacial, hostile, inimical, cool

combative [adjective]

means "aggressive"
warlike, bellicose, hostile, militant, belligerent, offensive

cynical [adjective]

means "asocial"
unfriendly, hostile, misanthropic, unsociable, antisocial

disinclined [adjective]

means "averse"
hostile, unwilling, reluctant, loath, opposed, inimical

embittered [adjective]

means "bitter"
ill-natured, resentful, antagonistic, rancorous, hostile, stern

factious [adjective]

means "insubordinate"
dissident, hostile, seditious, insurgent, opposing

icy [adjective]

means "character trait"
distant, aloof, cold, reserved, unfriendly, hostile

ill [adjective]

means "characteristic"
unfavourable, unkind, unkindly, adverse, hostile

ill-natured [adjective]

means "embittered"
bitter, resentful, antagonistic, rancorous, hostile, stern

jaundiced [adjective]

means "prejudiced"
grudging, envious, hostile, resentful, jealous, spiteful

misanthropic [adjective]

means "asocial"
unfriendly, hostile, antisocial, unsociable, cynical

opposite [adjective]

means "adverse"
opposing, antagonistic, hostile, inimical, opposed, refractory

rancorous [adjective]

means "embittered"
ill-natured, resentful, antagonistic, bitter, hostile, stern

repugnant [adjective]

means "antagonistic"
hostile, adverse, conflicting, contradictory, inimical

resentful [adjective]

means "embittered"
ill-natured, bitter, antagonistic, rancorous, hostile, stern

unconnected [adjective]

means "adverse"
hostile, opposed, extraneous, alien, unfriendly, different

unfeeling [adjective]

means "cold"
unfriendly, heartless, glacial, hostile, inimical, cool

unsociable [adjective]

means "asocial"
unfriendly, hostile, misanthropic, antisocial, cynical

unsympathetic [adjective]