SUPERFI'CIES, noun [Latin from super, upon, and facies, face.] The surface; the exterior part of a thing. A superficies consists of length and breadth; as the superficies of a plate or of a sphere. superficies is rectilinear, curvilinear, plane, convex or concave.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI