/ Dictionary / Index T tokamak: Meaning and Definition of Find definitions for: to•ka•mak Pronunciation: (tō'ku-mak", tok'u-), [key] — n. Physics. a type of experimental nuclear fusion reactor in which a plasma of atoms circulates in a toroidal tube and is confined to a narrow beam by an electromagnetic field. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: tokamak (Thesaurus) Tojo tokay Related Content Daily Word Quiz: panacea Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language