baby grand vs parlour grand piano

baby grand and parlour grand piano both are nouns.

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

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

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

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