hostilities vs combat

hostilities and combat both are nouns.

Word	Noun	Adjective	Verb	Adverb
hostilities	Yes	No	No	No
combat	Yes	No	Yes	No

As nouns, combat is a hypernym of hostilities; that is, combat is a word with a broader meaning than hostilities:

Other hypernyms of hostilities include armed combat.

hostilities (noun)	combat (noun)
fighting; acts of overt warfare	an engagement fought between two military forces
	the act of fighting; any contest or struggle

hostilities (verb)	combat (verb)
	battle or contend against in or as if in a battle