cathode
cathode Lexical Profile
cathode Game Scores & Validity
• noun
The electrode by which conventional electric current leaves a polarized electrical device, or the electrode where chemical reduction occurs in an electrochemical cell.
"During the electroplating process, metal ions in the solution migrate toward the cathode and form a thin coating on its surface."
The electron-emitting negative terminal in a vacuum tube, gas-filled tube, or semiconductor diode.
"When heated inside the vacuum tube, the cathode releases a steady stream of electrons toward the positively charged plate."
Word Nuance & Usage
The electrical polarity of a cathode depends on the device: in an electrolytic cell (which consumes power), the cathode is the negative terminal, whereas in a discharging galvanic cell or battery (which supplies power), the cathode is the positive terminal.
Word Origin & Etymology
Coined in 1834 by English polymath William Whewell for physicist Michael Faraday, from the Ancient Greek 'kathodos' meaning 'way down' or 'descent' (from 'kata-', down, and 'hodos', way), referring to the exit path of electric current.