ter·mi·nus / ˈtərmənəs/ • n. (pl. -ni / -nī/ or -nus·es) 1. a final point in space or time; an end or extremity: the exhibition's terminus is 1962. ∎  Biochem. the end of a polypeptide or polynucleotide chain or similar long molecule.2. chiefly Brit. the end of a railroad or other transportation route, or a station at such a point; a terminal. ∎  an oil or gas terminal.3. Archit. a figure of a human bust or an animal ending in a square pillar from which it appears to spring, originally used as a boundary marker in ancient Rome.

terminus in ancient Rome, a boundary marker consisting of a figure of a human bust or an animal ending in a square pillar from which it appears to spring. Terminus was originally the name of the deity who presided over boundaries and landmarks.

terminus. See term; terminal figure.