2) tetrahedron. The American HeritageŽ Dictionary of the English Language: Fourth Edition. 2000.
...Inflected forms: pl. tetˇraˇheˇdrons or tetˇraˇheˇdra (-dr) A polyhedron with four faces. Late Greek tetraedron, from Greek, neuter of tetraedros, four-faced : tetra-,...

3) Platonic Bodies. Dictionary of Phrase and Fable. 1898
...The five regular geometric solids described by Plato-viz. the tetrahedron, hexahedron, oct - hedron, dodecahedron, and icosahedron, all of which are bounded by like,...

4) tetrahedral. The American HeritageŽ Dictionary of the English Language: Fourth Edition. 2000.
...1. Of or relating to a tetrahedron. 2. Having four faces. tetraˇhedralˇly -ADVERB...

5) 95. Quaternity. Mawson, C.O. Sylvester. 1922. Roget s International Thesaurus of English Words and Phrases
...tetragon. quadrangle, quadrature, quadruplet; quatrefoil; tetragram, tetragrammaton; tetrahedron, tetraody, tetrology, quatrefoil or quadrefoil. VERB: SQUARE, biquadrate,...

6) tetrahedrite. The American HeritageŽ Dictionary of the English Language: Fourth Edition. 2000.
...German Tetraedrit, from Greek tetraedros, four-faced (from its four-faced crystals). See tetrahedron....

7) simplex. The American HeritageŽ Dictionary of the English Language: Fourth Edition. 2000.
...such as a line segment in one-dimensional space, a triangle in two-dimensional space, or a tetrahedron in three-dimensional space. 2. Linguistics A word that has...

8) XI. Splanchnology. 3b. 3. The Urinary Bladder. Gray, Henry. 1918. Anatomy of the Human Body.
...1 The Empty Bladder.—When hardened in situ, the empty bladder has the form of a flattened tetrahedron, with its vertex tilted forward. It presents a fundus, a vertex,...

9) polyhedron. The Columbia Encyclopedia, Sixth Edition. 2001
...solids, although they were known to the Greeks before the time of Plato. They are the tetrahedron, bounded by four equilateral triangles; the hexahedron, or cube,...

10) 244. Angularity. Mawson, C.O. Sylvester. 1922. Roget s International Thesaurus of English Words and Phrases
...pentagon, hexagon, heptagon, octagon, oxygon, decagon. Platonic bodies; cube, rhomboid; tetrahedron, pentahedron, hexahedron, octahedron, dodecahedron, icosahedron;...