burial mound vs tumulus

burial mound and tumulus both are nouns.

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

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

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

Other synonyms of burial mound include barrow, grave mound.

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