n. 1 a framework of spaced parallel bars; a grating. 2 a system of numbered squares printed on a map and forming the basis of map references. 3 a network of lines, electric-power connections, gas-supply lines, etc. 4 a pattern of lines marking the starting-places on a motor-racing track. 5 the wire network between the filament and the anode of a thermionic valve etc. 6 an arrangement of town streets in a rectangular pattern. grid bias Electr. a fixed voltage applied between the cathode and the control grid of a thermionic valve which determines its operating conditions. gridded adj.
[ back-form. f. GRIDIRON ]