gambrel roof vs saddleback roof

gambrel roof and saddleback roof both are nouns.

Word	Noun	Adjective	Verb	Adverb
gambrel roof	Yes	No	No	No
saddleback roof	Yes	No	No	No

As nouns, saddleback roof is a hypernym of gambrel roof; that is, saddleback roof is a word with a broader meaning than gambrel roof:

gambrel roof: a gable roof with two slopes on each side and the lower slope being steeper
saddleback roof: a double sloping roof with a ridge and gables at each end

Other hypernyms of gambrel roof include gable roof, saddle roof, saddleback.

gambrel roof (noun)	saddleback roof (noun)
a gable roof with two slopes on each side and the lower slope being steeper	a double sloping roof with a ridge and gables at each end