unfriendly vs hostile

unfriendly is not a noun while hostile is a noun.

Word	Noun	Adjective	Verb	Adverb
unfriendly	No	Yes	No	No
hostile	Yes	Yes	No	No

As adjectives, unfriendly and hostile are synonyms defined as:

Other synonyms of unfriendly include uncongenial.

unfriendly (noun)	hostile (noun)
	troops belonging to the enemy's military forces

unfriendly (adjective)	hostile (adjective)
not disposed to friendship or friendliness	characterized by enmity or ill will
not easy to understand or use	not belonging to your own country's forces or those of an ally
very unfavorable to life or growth	unsolicited and resisted by the management of the target company (used of attempts to buy or take control of a business)
not friendly	very unfavorable to life or growth
	impossible to bring into friendly accord