Roundhouse

Round"house` (?), n. 1. A constable's prison; a lockup, watch-house, or station house. [Obs.]

2. (Naut.) (a) A cabin or apartament on the after part of the quarter-deck, having the poop for its roof; -- sometimes called the coach. (b) A privy near the bow of the vessel.

3. A house for locomotive engines, built circularly around a turntable.