tetragonal (tetragonal)

[ 1. In geom., pertaining to a tetragon; having four angles or sides.-2. In bot. and zoöl., four angled; having four longitudinal angles.-3. Square; quartile. Sir T. Browne. - Tetragonal spheroid, a tetrahedron with isosceles faces. - Tetragonal stem, a stem that has four sides, as in many Labi atæ.-Tetragonal system, in crystal., that system in which the three axes are at right angles to each other, but the two equal lateral axes differ in length from the ver tical axis. See crystallography. Also dimetric, quadratic, mono dimetric, etc.