memorial park vs graveyard

memorial park and graveyard both are nouns.

Word	Noun	Adjective	Verb	Adverb
memorial park	Yes	No	No	No
graveyard	Yes	No	No	No

As nouns, memorial park and graveyard are synonyms defined as:

Other synonyms of memorial park include burial ground, burial site, burying ground, cemetery, necropolis.

memorial park (noun)	graveyard (noun)
a tract of land used for burials	a tract of land used for burials