platonic : Idioms & Phrases

• noun any one of five solids whose faces are congruent regular polygons and whose polyhedral angles are all congruent
  ideal solid; Platonic body; regular polyhedron; regular convex polyhedron; regular convex solid.
  

WordNet

• the five regular geometrical solids; namely, the tetrahedron, hexahedron or cube, octahedron, dodecahedron, and icosahedron.

Webster 1913

• noun any one of five solids whose faces are congruent regular polygons and whose polyhedral angles are all congruent
  ideal solid; Platonic body; regular polyhedron; regular convex polyhedron; regular convex solid.
  

WordNet

• a pure, spiritual affection, subsisting between persons of opposite sex, unmixed with carnal desires, and regarding the mind only and its excellences; a species of love for which Plato was a warm advocate. = Platonic relation

Webster 1913

• noun any one of five solids whose faces are congruent regular polygons and whose polyhedral angles are all congruent
  ideal solid; Platonic body; regular polyhedron; regular convex polyhedron; regular convex solid.
  

WordNet

• noun time required for one complete cycle of the precession of the equinoxes, about 25,800 years
  great year.
  

WordNet

• (Astron.), a period of time determined by the revolution of the equinoxes, or the space of time in which the stars and constellations return to their former places in respect to the equinoxes; called also great year. This revolution, which is caused by the precession of the equinoxes, is accomplished in about 26,000 years. Barlow.

Webster 1913