Meaning of GRID in English

in an electron tube, an electrode that has one or more openings for controlling electrons or ions as they pass through it. Unmodified, the term applies to a control grid, which is ordinarily placed between a cathode and an anode (or plate) of an electron tube to initiate or vary the current between two or more electrodes. A screen gridusually maintained at a fixed potentialis placed between a control grid and an anode to reduce the electrostatic influence of the plate on the control grid. A suppressor grid is interposed between two positive electrodesusually the screen grid and the anodeto reduce the flow of secondary electrons from one to the other.

Britannica English vocabulary.      Английский словарь Британика.