Definition

A series of lines, usually straight and paral­lel, superimposed on a CHART or PLOTTING SHEET to serve as a directional reference for NAVIGATION. See also GRATICULE. Two sets of mutually perpendicular lines dividing a MAP, CHART, or other representation of the EARTH's surface, into squares or rectangles to permit location of any point by a system of RECTANGULAR COORDINATES. In electronics, an electrode with one or more openings to permit passage of electrons or ions.