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The Clue
Some vacuum tubes (7 letter answer)
The Answer
TRIODES
Tags
Notes
The answer TRIODES is so rare that it appears less than once every 2900 puzzles.
Related Clues
Electron tubes
Vacuum tubes
Old TV tubes
Definition
TRIODE as a noun:
1. a thermionic vacuum tube having three electrodes; fluctuations of the charge on the grid control the flow from cathode to anode which making amplification possible