Definition of tetragonal

• a. - Of or pertaining to a tetragon; having four angles or sides; thus, the square, the parallelogram, the rhombus, and the trapezium are tetragonal fingers.
• a. - Having four prominent longitudinal angles.
• a. - Designating, or belonging to, a certain system of crystallization; dimetric. See Tetragonal system, under Crystallization.