D defs.my
Entry 3 senses Webster, 1913

Tetragonal

· Te·trag·o·nal · IPA /tɛˈtɹæɡənəl/
01 a. Of or pertaining to a tetragon; having four angles or sides; thus, the square, the parallelogram, the rhombus, and the trapezium are tetrag…
  1. 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.(Geom.)
  2. 2.
    Having four prominent longitudinal angles.(Bot.)
  3. 3.
    Designating, or belonging to, a certain system of crystallization; dimetric. See Tetragonal system, under Crystallization.(Crystallog.) See: Crystallization