What does kathode mean?
A kathode is an electrode associated with reduction and, in an electrolytic cell, is the electrode toward which conventional current flows. It is commonly the negative electrode during electrolysis, where dissolved metal ions may be deposited on its surface. In vacuum tubes, transistors, and similar electronic devices, a kathode serves as the terminal from which electrons are emitted or injected. The term is an alternative spelling of “cathode,” with the latter being the more usual modern spelling, especially in American English. Although a kathode is often understood simply as the opposite of an anode, its precise identity can vary with the system: in a galvanic cell, for example, reduction still occurs at the kathode even though it may have positive polarity. The word is chiefly technical and appears in discussions of electrochemistry, electronics, vacuum tubes, and cathode-ray equipment.
nounA kathode is an electrode toward which conventional current flows in an electrolytic cell. In vacuum and other electron tubes, it is the terminal from which electrons are emitted.
- The electrode toward which conventional current flows in an electrolytic cell.
- The electron-emitting terminal in a vacuum tube or similar electron device.
"The kathode released electrons that were attracted to the anode."
"As current passed through the solution, the kathode became coated with deposited metal."
"Electrons left the heated kathode and crossed the vacuum toward the anode."
The regular plural adds -s.
"Two kathodes were placed at opposite ends of the electrolytic cell."
The name means “way down”: it comes from Greek elements meaning “down” and “way,” reflecting the movement of electrons toward the cathode.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does kathode come from?
The word comes from the Greek kathodos, meaning “descent” or “way down,” formed from kata, “down,” and hodos, “way” or “path.” Scientific usage developed through the electrolysis terminology associated with the anode and cathode, with the negative electrode described as the path or seat of descending current. “Kathode” is a less common spelling of “cathode,” which comes from the same Greek source.
Related word forms
How kathode is actually used
The spelling is now less common than cathode. In an electrolytic cell the kathode is negative, whereas in a galvanic cell it may be positive; in electron tubes, its identifying function is to emit electrons.
Easily confused with kathode
Kathode is an alternative spelling of cathode; cathode is the more common modern form, especially in American English.