combat vs struggle

combat and struggle both are nouns.

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

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

Other hypernyms of combat include battle, conflict.

As verbs, struggle is a hypernym of combat; that is, struggle is a word with a broader meaning than combat:

Other hypernyms of combat include contend, fight.

combat (noun)	struggle (noun)
an engagement fought between two military forces	strenuous effort
the act of fighting; any contest or struggle	an energetic attempt to achieve something
	an open clash between two opposing groups (or individuals)

combat (verb)	struggle (verb)
battle or contend against in or as if in a battle	be engaged in a fight; carry on a fight
	to exert strenuous effort against opposition
	climb awkwardly, as if by scrambling
	make a strenuous or labored effort