sofa: an upholstered seat for more than one person
instrumentality: an artifact (or system of artifacts) that is instrumental in accomplishing some end
belemnite: a conical calcareous fossil tapering to a point at one end and with a conical cavity at the other end containing (when unbroken) a small chambered phragmocone from the shell of any of numerous extinct cephalopods of the family Belemnitidae