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

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The recycled cathode active materials include lithium, nickel, cobalt and manganese. — Prabhat Ranjan Mishra, Interesting Engineering, 19 Sep. 2026 Hydrogen forms at the cathode, while oxygen is produced at the anode. — New Atlas, 3 Sep. 2026 Once a fixture of the American experience, the custom of collectively huddling around the cathode-ray hearth has largely been supplanted by the isolationist practices of the smartphone era. — Anthony Crupi, Sportico.com, 19 Aug. 2026 The differences in the cathode, anode, and cellular structure lower charging resistance and heat generation during charging. — Eric Zeman, PC Magazine, 22 July 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

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Cite this Entry

“Cathode.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/cathode. Accessed 26 Sep. 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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