The sac of silk taken from a silkworm (when ready to spin its cocoon), for the purpose of drawing it out into a thread. This, when dry, is exceedingly strong, and is used as the snood of a fish line.
Grand Unified Theory. A theory, not yet developed, that will supposedly describe the strong, weak, and electromagnetic forces as different aspects of a single force. See also: strong force, weak force, electromagnetic force, Theory of Everything, Advanced Topics
grand unified theory. A model for unifying the strong nuclear force, the weak nuclear force, and the electromagnetic force at very high energies. Ultimately, it is hoped to extend GUT to incorporate gravity (possibly by superstrings) to create a theory of everything (TOE). Several such GUTs have been proposed, but not yet experimentally verified.