ground ball vs groundball

ground ball and groundball both are nouns.

Word	Noun	Adjective	Verb	Adverb
ground ball	Yes	No	No	No
groundball	Yes	No	No	No

As nouns, ground ball and groundball are synonyms defined as:

ground ball and groundball: (baseball) a hit that travels along the ground

Other synonyms of ground ball include grounder, hopper.

ground ball (noun)	groundball (noun)
(baseball) a hit that travels along the ground	(baseball) a hit that travels along the ground