Cathode /(?)/

Cath·ode

Cathode

n.
  1. The part of a voltaic battery by which the electric current leaves substances through which it passes, or the surface at which the electric current passes out of the electrolyte; the negative pole; -- opposed to anode. (Physics)

Phrases & Compounds
Cathode ray
a kind of ray generated at the cathode in a vacuum tube, by the electrical discharge<-- X-ray -->.