'Regular tetrahedron' definitions:

Definition of 'regular tetrahedron'

From: WordNet
noun
A tetrahedron with four equilateral triangular faces

Definition of 'Regular tetrahedron'

From: GCIDE
  • Tetrahedron \Tet`ra*he"dron\, n. [Tetra- + Gr. ? seat, base, fr. ? to sit.] (Geom.) A solid figure inclosed or bounded by four triangles. [1913 Webster]
  • Note: In crystallography, the regular tetrahedron is regarded as the hemihedral form of the regular octahedron. [1913 Webster]
  • Regular tetrahedron (Geom.), a solid bounded by four equal equilateral triangles; one of the five regular solids. [1913 Webster]