tokamak definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
a reactor designed to control nuclear fusion in a plasma of ions and electrons inside a doughnut-shaped, or toroidal, magnetic bottle
Origin: ; from Russian acronym for a “toroidal magnetic chamber”
tokamak definition by American Heritage Dictionary
A doughnut-shaped chamber used in fusion research in which a plasma is heated and confined by magnetic fields.
Origin: Russian, from to(roidal'naya) kam(era s) ak(sial'nym magnitnym polem), toroidal chamber with axial magnetic field.