cathode

[ kath-ohd ]

noun

1. the electrode or terminal by which current leaves an electrolytic cell, voltaic cell, battery, etc.
2. the positive terminal of a voltaic cell or battery.
3. the negative terminal, electrode, or element of an electron tube or electrolytic cell.

cathode

/ kæˈθɒdɪk; -ˈθəʊ-; ˈkæθəʊd; kæˈθəʊdəl /

noun

1. the negative electrode in an electrolytic cell; the electrode by which electrons enter a device from an external circuit
2. the negatively charged electron source in an electronic valve
3. the positive terminal of a primary cell

cathode

/ kăth′ōd′ /

1. 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.
2. The source of electrons in an electrical device, such as a vacuum tube or diode.
3. 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.
4. Compare anode

Derived Forms

• cathodal, adjective

Word History and Origins

Origin of cathode¹

1825–35; < Greek káthodos a way down, equivalent to kat- cat- ( def ) + hodós way

Word History and Origins

Origin of cathode¹

C19: from Greek kathodos a descent, from kata- down + hodos way

Example Sentences

Every zinc-air battery cell contains two electrodes — a zinc anode and a porous cathode — separated by a liquid called an electrolyte.

From Science News

Nearly all of that lithium then returns to the cathode during the discharge cycle.

From MIT Technology Review

Xiaomi has also jettisoned the reflective cathode layer that would normally make the screen opaque, even when there’s no image.

From Popular-Science

The carmaker’s decision to make its own battery cells, and to enter production of battery cathodes and associated raw materials, is intended to add in-house capacity alongside deals with external suppliers as demand for electric vehicles rises.

From Fortune

The cathode can be one of several lithium-containing materials.

From Science News For Students

His discovery was in effect that electric rays emanated from the part of the tube struck by the cathode rays.

From Project Gutenberg

The plate where the current goes out, the cathode, C, increases in weight since some of the silver is deposited.

From Project Gutenberg

The diagram, of the tube shows that the main tube has been expanded round the edges of the cathode.

From Project Gutenberg

This is to reduce the heating consequent on the projection of cathode rays from the edges of the disc against the glass tube.

From Project Gutenberg

When the annealing is finished the side tube is bent as shown to serve as a handle when the time comes to mount the cathode.

From Project Gutenberg