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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Alongside the anode and cathode, the electrolyte is one of the three essential battery components. Jijo Malayil, Interesting Engineering, 5 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 9 Aug. 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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