1. Fireplace or hearth.
2. Fireplace with flue and vent over it, so including the structure rising above a roof or outside the building. A chimney-stack could be a large structure surrounded by a timber-framed building, where it helped to stabilize the structure as well as providing heat, could be erected over the gable-end, or placed in series along a façade, as in a medieval hospital or almshouse (e.g. St John's Hospital, Lichfield, Staffs. (late C15), with its array of stacks). In Elizabethan and Jacobethan prodigy-houses chimney-stacks contributed to the complex skylines of the composition.
The following terms are associated with chimneys: fireplace (opening of a chimney into a room, whether decorated or not); gathering (part of the flue that contracts with the ascent); hearth (floor of the fireplace); and inglenook (small space beside the chimney, often containing seats, sometimes illuminated by means of a small window, and occasionally having a lower ceiling than in the rest of the room, hence its other name, roofed ingle).
chim·ney / ˈchimnē/ • n. (pl. -neys) a vertical channel or pipe that conducts smoke and combustion gases up from a fire or furnace and typically through the roof of a building. ∎ the part of such a structure that extends above the roof. ∎ a glass tube that protects the flame of a lamp. ∎ a steep narrow cleft by which a rock face may be climbed. ORIGIN: Middle English (denoting a fireplace or furnace): from Old French cheminee ‘chimney, fireplace,’ from late Latin caminata, perhaps from camera caminata ‘room with a fireplace,’ from Latin caminus ‘forge, furnace,’ from Greek kaminos ‘oven.’