(1):
(a.) Having four prominent longitudinal angles.
(2):
(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.
(3):
(a.) Designating, or belonging to, a certain system of crystallization; dimetric. See Tetragonal system, under Crystallization.