(1) Liquefaction, as by melting by heat. (2) Union, as by joining together, e.g., bone fusion. (3) The blending of slightly different images from each eye into a single perception. (4) The joining of two or more adjacent teeth during their development by a dentinal union.concrescence. (5) Joining of two genes, often neighboring genes. (6) The joining of two bones into a single unit, thereby obliterating motion between the two. (7) The process in which two membranes are joined together. [L. fusio, a pouring, fr. fundo, pp. fusus, to pour]