Noun

1. A rectangular array of squares or rectangles of equal size, such as in a crossword puzzle.
2. A system for delivery of electricity, consisting of various substations, transformers and generators, connected by wire.

   You can't turn off the building from here; you have to shut down the whole grid. — line from the motion picture Die Hard

3. A system or structure of distributed computers working mostly on a peer-to-peer basis, such structures being known as a computational grid or simply grid computing, and used mainly to solve single and complex scientific or technical problems or to process data at high speeds (as in clusters).
4. A method of marking off maps into areas.

Verb

1. To mark with a grid.
2. To assign a reference grid to.