groundball vs ground ball

groundball and ground ball both are nouns.

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

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

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

Other synonyms of groundball include grounder, hopper.

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