BASEMENT (5 letters) The term 'LOWER ROOM' can be solved by two crossword solutions: CELLAR (6 letters) and BASEMENT (5 letters). A CELLAR is an underground room, usually located beneath a building, used for storage or as a wine CELLAR. A BASEMENT is a storey of a building that is either completely or partially below the ground floor. Basements are typically used as a utility space for a building, where such items as the furnace, water heater, breaker panel or fuse box, and air-conditioning system are located; it may also be used as living space.