Control grid and Electrode

Control grid noun - An electrode placed between the cathode and anode of a vacuum tube to control the flow of electrons through the tube.

Electrode and control grid are semantically related. In some cases you can use "Electrode" instead a noun phrase "Control grid".

Electrode noun - A conductor used to make electrical contact with some part of a circuit.

Control grid and electrode are semantically related. Sometimes you can replace phrase "Control grid" with "Electrode", this terms are similar.