TRISOCTAHEDRA
Noun
trisoctahedra
plural of trisoctahedron
Source: Wiktionary
TRISOCTAHEDRON
Tris*oc`ta*he"dron, n. Etym: [Gr. octahedron.] (Crystallog.)
Definition: A solid of the isometric system bounded by twenty-four equal
faces, three corresponding to each face of an octahedron. Tetragonal
trisoctahedron, a trisoctahedron each face of which is a
quadrilateral; called also trapezohedron and icositetrahedron.
– Trigonal trisoctahedron, a trisoctahedron each face of which is
an isosceles triangle.
Source: Webster’s Unabridged Dictionary 1913 Edition