mansard roof vs mansard

mansard roof and mansard both are nouns.

Word	Noun	Adjective	Verb	Adverb
mansard roof	Yes	No	No	No
mansard	Yes	Yes	No	No

As nouns, mansard roof and mansard are synonyms defined as:

mansard roof (noun)	mansard (noun)
a hip roof having two slopes on each side	a hip roof having two slopes on each side

mansard roof (adjective)	mansard (adjective)
	(of a roof) having two slopes on all sides with the lower slope steeper than the upper