cath·ode   (kāth'ōd')    n.   Abbr. ka A negatively charged electrode, as of an electrolytic cell, a storage battery, or an electron tube. The positively charged terminal of a primary cell or a storage battery that is supplying current. [Greek kathodos, descent : kat-, kata-, cata- + hodos, way, path.] ca·thod'ic (kā-thŏd'ĭk) adj., ca·thod'i·cal·ly adv.

Cathode

Cath"ode\, n. [Gr. ? descent; ? down + ? way.] (Physics) 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. --Faraday.

Cathode ray (Phys.), a kind of ray generated at the cathode in a vacuum tube, by the electrical discharge .

cathode 

Main Entry: cath·ode
Pronunciation: 'kath-"Od
Function: noun
1 : the electrode of an electrochemical cell at which reduction occurs: as a : the negative terminal of an electrolytic cell b : the positive terminal of a storage battery that is delivering current
2 : theelectron-emitting electrode of an electron tube —compare ANODE

cathode   (kāth'ōd')  Pronunciation Key  The negative electrode in an electrolytic cell, toward which positively charged particles are attracted. The cathode has a negative charge because it is connected to the negatively charged end of an external power supply. The source of electrons in an electrical device, such as a vacuum tube or diode. The positive electrode of a voltaic cell, such as a battery. The cathode gets its positive charge from the chemical reaction that happens inside the battery, not from an external source. Compare anode.