noun

1. a small structure, esp. one with a sloping roof, attached to a larger building
2. a sloping roof, or, sometimes, an awning, etc. extending out from a wall or building
3. 1. an apartment or other houselike structure built on the roof of a building
   2. a luxury apartment on an upper floor, esp. the top floor of a building

Etymology: altered (infl. by house) < pentice < ME pentis, penthouse < MFr apentis < ML appenticium < LL appendicium, lit., an appendage < L appendere: see append