Di`a*caus"tic (?), a. [Pref. dia- + caustic.] (Opt.) Pertaining to, or possessing the properties of, a species of caustic curves formed by refraction. See Caustic surface, under Caustic.

Di`a*caus"tic, n. 1. (Med.) That which burns by refraction, as a double convex lens, or the sun's rays concentrated by such a lens, sometimes used as a cautery.

2. (Math.) A curved formed by the consecutive intersections of rays of light refracted through a lens.