hemihedral

1 definition found

hemihedral - Collaborative International Dictionary of English v.0.48 :

  Hemihedral \Hem`i*he"dral\, a. [Hemi- + Gr. ? seat, base, fr. ?
     to sit.] (Crystallog.)
     Having half of the similar parts of a crystals, instead of
     all; consisting of half the planes which full symmetry would
     require, as when a cube has planes only on half of its eight
     solid angles, or one plane out of a pair on each of its
     edges; or as in the case of a tetrahedron, which is
     hemihedral to an octahedron, it being contained under four of
     the planes of an octahedron. -- Hem`i*he"dral*ly, adv.
     [1913 Webster]