Noun thermionic tube has 1 sense
  1. tube, vacuum tube, thermionic vacuum tube, thermionic tube, electron tube, thermionic valve - electronic device consisting of a system of electrodes arranged in an evacuated glass or metal envelope
    --1 is a kind of electronic device
    --1 is a part of circuit, electrical circuit, electric circuit
    --1 has parts:
     anode; cathode; electrode; grid, control grid; plate
    --1 has particulars:
     acorn tube; diode, rectifying tube, rectifying valve; electron multiplier; gas-discharge tube; klystron; magnetron; pentode; television-camera tube, television pickup tube; tetrode; triode; X-ray tube