1
: the electrode of an electrochemical cell at which reduction occurs:
a
: the negative terminal of an electrolytic cell
b
: the positive terminal of a galvanic cell
2
: the electron-emitting electrode of an electron tube
broadly : the negative electrode of a diode compare anode
cathodally adverb

Examples of cathode in a Sentence

Recent Examples on the Web
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South Korean research team has designed a dry thick-film cathode technology using porous graphitic carbon nitride as a cathode additive. — Mrigakshi Dixit, Interesting Engineering, 30 Sep. 2026 Hydrogen forms at the cathode, while oxygen is produced at the anode. — New Atlas, 3 Sep. 2026 See All Example Sentences for cathode

Word History

Etymology

Greek kathodos way down, from kata- + hodos way

First Known Use

1834, in the meaning defined at sense 1

Time Traveler
The first known use of cathode was in 1834

Browse Nearby Words

Cite this Entry

“Cathode.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/cathode. Accessed 5 Oct. 2026.

Kids Definition

1
: the negative electrode of an electrolytic cell compare anode sense 1
2
: the positive terminal of a battery
3
: the electron-emitting electrode of an electron tube

Medical Definition

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
: the electron-emitting electrode of an electron tube compare anode

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