ruler

One, such as a monarch or dictator, that rules or governs.

A straightedged strip, as of wood or metal, for drawing straight lines and measuring lengths.

One who rules or governs; one who exercises dominion or controlling power over others; a person who commands, manages, restrains, or has part in the making or administration of law; one in authority.

A rule; an instrument made of wood, brass, ivory, or the like, with straight edges or sides, by means of which, as a guide, straight lines may be drawn on paper, parchment, or other substance, by passing a pen or pencil along the edge. (See rule, and parallel ruler, under parallel.) When a ruler has the lines of chords, tangents, sines, etc., it is called a scale. See scale.

In engraving, a workman who operates a ruling-machine for ruling in flat tints, etc. See ruling-machine.