mound vs grave mound

mound and grave mound both are nouns.

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

As nouns, grave mound is a hyponym of mound; that is, grave mound is a word with a more specific, narrower meaning than mound:

mound: structure consisting of an artificial heap or bank usually of earth or stones
grave mound: (archeology) a heap of earth placed over prehistoric tombs

Other hyponyms of mound include barbette, barrow, burial mound, tumulus, embankment, snow bank, snowbank.

mound (noun)	grave mound (noun)
the position on a baseball team of the player who throws the ball for a batter to try to hit	(archeology) a heap of earth placed over prehistoric tombs
structure consisting of an artificial heap or bank usually of earth or stones
(baseball) the slight elevation on which the pitcher stands
a collection of objects laid on top of each other
a small natural hill

mound (verb)	grave mound (verb)
form into a rounded elevation