Cathode makes reference to the terminal on an electrical device from which a major flow of electrons takes place a or from which electric current flows, an in a battery.

The converse of anode. The term also sometimes used to refer to the negative side of a solid state diode. In tubes the cathode is the source of a cathode-ray, or a cloud of electrons that moves towards the oppositely changed anode.

-see also:
"Cathode" is in the HS Code "8540"
  Thermionic, Cold Cathode Or Photo-Cathode Valves And Tubes ( For Example, Vacuum Or Vapour Or Gas Fi