Search Result for "triode": 
Wordnet 3.0

NOUN (1)

1. a thermionic vacuum tube having three electrodes; fluctuations of the charge on the grid control the flow from cathode to anode which makes amplification possible; 



WordNet (r) 3.0 (2006):

triode
    n 1: a thermionic vacuum tube having three electrodes;
         fluctuations of the charge on the grid control the flow
         from cathode to anode which makes amplification possible