Meaning of quantum theory

quan'tum the"ory

Pronunciation: [key]
— Physics. Physics.
  1. any theory predating quantum mechanics that encompassed Planck's radiation formula and a scheme for obtaining discrete energy states for atoms, as Bohr theory.
  2. any theory that treats certain phenomena by the methods of quantum mechanics: a quantum theory of gravitation.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.