outbuilding n 1: a building that is subordinate to and separate from a main building
Outbuild \Out*build"\, v. t. [imp. & p. p. {Outbuilt}or {Outbuilded}; p. pr. & vb. n. {Outbuilding}.] To exceed in building, or in durability of building. [1913 Webster]
Outbuilding \Out"build`ing\, n. A building separate from, and subordinate to, the main house; an outhouse. [1913 Webster]
18 Moby Thesaurus words for "outbuilding": Nissen hut, Quonset hut, booth, crib, gatehouse, hut, hutch, kiosk, lean-to, outhouse, pavilion, sentry box, shack, shanty, shed, stall, tollbooth, tollhouse