A ~ is something which is in a pattern of straight lines that cross over each other, forming squares. On maps the ~ is used to help you find a particular thing or place.
...a ~ of ironwork.
...a ~ of narrow streets...
Many canals were built along map ~ lines.
see also cattle ~
A ~ is a network of wires and cables by which sources of power, such as electricity, are distributed throughout a country or area.
...breakdowns in communications and electric power ~s.
The ~ or the starting ~ is the starting line on a car-racing track.
The Ferrari of Alain Prost will be second on the ~.