Grid  n. 1 grating. 2 system of numbered squares printed on a map and forming the basis of map references. 3 network of lines, electric-power connections, gas-supply lines, etc. 4 pattern of lines marking the starting-places on a motor-racing track. 5 perforated electrode controlling the flow of electrons in a thermionic valve etc. 6 arrangement of town streets in a rectangular pattern. [from *gridiron]