outbuilding vs outhouse

outbuilding and outhouse both are nouns.

Word	Noun	Adjective	Verb	Adverb
outbuilding	Yes	No	No	No
outhouse	Yes	No	No	No

As nouns, outhouse is a hyponym of outbuilding; that is, outhouse is a word with a more specific, narrower meaning than outbuilding:

outbuilding: a building that is subordinate to and separate from a main building
outhouse: a small outbuilding with a bench having holes through which a user can defecate

Other hyponyms of outbuilding include carriage house, coach house, remise, garage, dog house, doghouse, kennel, earth-closet, jakes, privy, shed.

outbuilding (noun)	outhouse (noun)
a building that is subordinate to and separate from a main building	a small outbuilding with a bench having holes through which a user can defecate