n. The act of linking; the state of being linked; also, a system of links.n. Manner of linking or of being linked; -- said of the union of atoms or radicals in the molecule.n. 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.n. Any object, factor, or relationship that creates a bond or association between two other objects.n. The proximity of two or more genes on the genome of an organism that causes those genes to be inherited, transferred, or moved together with a frequency greater than for genes not associated. The linkage is a continuous variable, and is inversely related to the distance between genes on the genome.