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