Pronunciation: (te"tru-hē'drun), [key] —pl. -drons,
-draPronunciation: (-dru). [key] 1. Geom.a solid contained by
four plane faces; a triangular pyramid. 2. any of various
objects resembling a tetrahedron in the distribution of its
faces or apexes. Random House Unabridged Dictionary, Copyright ©
1997, by Random House, Inc., on Infoplease.