Tetragonal

Part of speech: adjective (a.)

1. Of or pertaining to a tetragon; having four angles or sides; thus, the square, the parallelogram, the rhombus, and the trapezium are tetragonal fingers.

2. Having four prominent longitudinal angles.

3. Designating, or belonging to, a certain system of crystallization; dimetric. See Tetragonal system, under Crystallization.