Definitions:
a framework of spaced bars that are parallel to or cross each other; a grating

a network of lines that cross each other to form a series of squares or rectangles

a network of cables or pipes for distributing power, especially high-voltage transmission lines for electricity

an electrode placed between the cathode and anode of a thermionic valve or cathode ray tube, serving to control or modulate the flow of electrons.

put into or set out as a grid