·noun The act of linking; the state of being linked; also, a system of links.
II. Linkage ·noun Manner of linking or of being linked;
— said of the union of atoms or radicals in the molecule.
III. Linkage ·noun A system of straight lines or bars, fastened together by joints, and having certain of their points fixed in a plane. It is used to describe straight lines and curves in the plane.