Te*trag"o*nal (?), a.
1. Geom.
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. Bot.
Having four prominent longitudinal angles.
3. Crystallog.
Designating, or belonging to, a certain system of crystallization; dimetric. See Tetragonal system, under Crystallization.
© Webster 1913.