Definition of: trisoctahedron

(tris·ok′tə·hē′drən) noun plural ·dra (-drə)
1. A solid having 24 equal faces corresponding by threes to the faces of an octahedron.
2. A holohedral isometric crystal included under 24 equal isosceles triangular faces with eight planes meeting at the extremities of the rectangular axes: also trigonal trisoctahedron.
3. An isometric holohedron included under 24 similar and equal trapeziform faces; a trapezohedron: also tetragonal trisoctahedron. [<Gk. tris thrice (<treis three) + OCTAHEDRON.]
—tris·oc′ta·he′dral adjective