home base vs home plate

home base and home plate both are nouns.

Word	Noun	Adjective	Verb	Adverb
home base	Yes	No	No	No
home plate	Yes	No	No	No

As nouns, home base and home plate are synonyms defined as:

home base and home plate: (baseball) base consisting of a rubber slab where the batter stands; it must be touched by a base runner in order to score

Other synonyms of home base include home, plate.

home base (noun)	home plate (noun)
(usually plural) the office that serves as the administrative center of an enterprise	(baseball) base consisting of a rubber slab where the batter stands; it must be touched by a base runner in order to score
(baseball) base consisting of a rubber slab where the batter stands; it must be touched by a base runner in order to score