grave mound vs tumulus

grave mound and tumulus both are nouns.

Word	Noun	Adjective	Verb	Adverb
grave mound	Yes	No	No	No
tumulus	Yes	No	No	No

As nouns, grave mound and tumulus are synonyms defined as:

grave mound and tumulus: (archeology) a heap of earth placed over prehistoric tombs

Other synonyms of grave mound include barrow, burial mound.

grave mound (noun)	tumulus (noun)
(archeology) a heap of earth placed over prehistoric tombs	(archeology) a heap of earth placed over prehistoric tombs