control grid vs electrode

control grid and electrode both are nouns.

Word	Noun	Adjective	Verb	Adverb
control grid	Yes	No	No	No
electrode	Yes	No	No	No

As nouns, electrode is a hypernym of control grid; that is, electrode is a word with a broader meaning than control grid:

control grid: an electrode placed between the cathode and anode of a vacuum tube to control the flow of electrons through the tube
electrode: a conductor used to make electrical contact with some part of a circuit

control grid (noun)	electrode (noun)
an electrode placed between the cathode and anode of a vacuum tube to control the flow of electrons through the tube	a conductor used to make electrical contact with some part of a circuit