mound over vs mound

mound over is not a noun while mound is a noun.

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

As verbs, mound is a hypernym of mound over; that is, mound is a word with a broader meaning than mound over:

mound over (noun)	mound (noun)
	the position on a baseball team of the player who throws the ball for a batter to try to hit
	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 over (verb)	mound (verb)
form mounds over	form into a rounded elevation
form a mound over