{ Pris*mat"ic (?), Pris*mat"ic*al (?), } a. [Cf. F. prismatique.] 1. Resembling, or pertaining to, a prism; as, a prismatic form or cleavage.

2. Separated or distributed by a prism; formed by a prism; as, prismatic colors.

3. (Crystallog.) Same as Orthorhombic.

Prismatic borax(Chem.), borax crystallized in the form of oblique prisms, with ten molecules of water; -- distinguished from octahedral borax. -- Prismatic colors(Opt.), the seven colors into which light is resolved when passed through a prism; primary colors. See Primary colors, under Color. -- Prismatic compass(Surv.), a compass having a prism for viewing a distant object and the compass card at the same time. -- Prismatic spectrum(Opt.), the spectrum produced by the passage of light through a prism.