Diacaustic :: Diacaustic (a.) Pertaining to, or possessing the properties of, a species of caustic curves formed by refraction. See Caustic surface, under Caustic..
Diacaustic :: Diacaustic (n.) 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..
Diacaustic :: Diacaustic (n.) A curved formed by the consecutive intersections of rays of light refracted through a lens.