epos vs heroic poem

epos and heroic poem both are nouns.

Word	Noun	Adjective	Verb	Adverb
epos	Yes	No	No	No
heroic poem	Yes	No	No	No

As nouns, epos and heroic poem are synonyms defined as:

Other synonyms of epos include epic, epic poem.

epos (noun)	heroic poem (noun)
a long narrative poem telling of a hero's deeds	a long narrative poem telling of a hero's deeds
a body of poetry that conveys the traditions of a society by treating some epic theme