brown sauce vs mainland China

brown sauce and mainland China both are nouns.

Word	Noun	Adjective	Verb	Adverb
brown sauce	Yes	No	No	No
mainland China	Yes	No	No	No

brown sauce (noun)	mainland China (noun)
bouillon or beef stock thickened with butter and flour roux and variously seasoned with herbs or Worcestershire etc.	a communist nation that covers a vast territory in eastern Asia; the most populous country in the world
a sauce based on soy sauce