Tet`ra*he"dral (?), a. [See Tetrahedron.]
Having, or composed of, four sides.
2. Crystallog. (a)
Having the form of the regular tetrahedron.
Pertaining or related to a tetrahedron, or to the system of hemihedral forms to which the tetrahedron belongs.
Tetrahedral angle Geom., a solid angle bounded or inclosed by four plane angles.
© Webster 1913.