# cathode

/ˈkæˌθoʊd/ (US) · /kˈæθəʊd/ (UK)

Source: https://englishreference.com/word/cathode
Updated: 2026-08-27

## Senses

### 1. electrical terminal

noun · CEFR C2 · Technical

the part of a battery or electrical part where the positive current flows out.

For teachers: the electrode of an electrochemical cell or polarized device through which positive electric current flows outward, corresponding to an inward flow of electrons.

- In a standard battery, the cathode is the positive end that you connect to your device.
- During the discharge of a galvanic cell, the cathode acts as the positive terminal where the reduction reaction occurs.

### 2. vacuum tubes

noun · CEFR C2 · Technical

the part in a vacuum tube or old TV screen that sends out electrons.

For teachers: the electrode in a vacuum tube or gas-filled tube that serves as the source of emitted electrons.

- Old television sets used a cathode ray tube to beam images onto the screen.
- The heated cathode emits a stream of electrons which are then accelerated toward the anode to create a functional circuit within the vacuum.

## Examples

- The battery has both an anode and a cathode.
- In a standard lithium-ion battery, lithium ions move from the anode to the cathode during discharge to power the device.
- The efficiency of the electrochemical reaction depends heavily on the surface area and material composition of the cathode, which facilitates the reduction process within the cell.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.