Definition of: penthouse

(pent′hous′) noun
1. An apartment or dwelling on the roof of a building.
2. A shed or roof with a single slope affixed to the wall of another building.
3. A small building, generally one–storied, adjoined to the wall of another building; an annex.
4. A canopy or awning projecting above a doorway or window. [Alter. of pentice, ME pentis, aphetic form of OF apentis, apendis <LL appendicium, lit., an appendage <L appendere APPEND]