From The Collaborative International Dictionary of English v.0.48:
Grid \Grid\ (gr[i^]d), n.
1. A grating of thin parallel bars, similar to a gridiron.
[1913 Webster]
2. (Elec.) A plate or sheet of lead with perforations, or
other irregularities of surface, by which the active
material of a secondary battery or accumulator is
supported.
[Webster 1913 Suppl.]
3. (Electronics) a mesh or coil of fine wire in an electron
tube, connected to the circuit so as to regulate the
current passing through the tube.
[PJC]
4. any network of crossing horizontal and vertical lines; --
they are used, for example, as reference coordinates to
locate objects or places on a map.
[PJC]
5. anything resembling a grid[4], as the Manhattan street
grid. See also gridlock.
[PJC]
6. a network of connected conductors for distributing
electrical power, especially one using high-tension lines
for wide geographic distribution of power; as, the
Northeast power grid.
[PJC]
7. (Football) the gridiron.
[PJC]