parlor grand vs parlour grand piano

parlor grand and parlour grand piano both are nouns.

Word	Noun	Adjective	Verb	Adverb
parlor grand	Yes	No	No	No
parlour grand piano	Yes	No	No	No

As nouns, parlor grand and parlour grand piano are synonyms defined as:

Other synonyms of parlor grand include baby grand, baby grand piano, parlor grand piano, parlour grand.

parlor grand (noun)	parlour grand piano (noun)
a small grand piano	a small grand piano