parallel rulers


plural noun

a pair of straightedges connected by two pivoted crosspieces of equal length so as to be parallel at all times, used for various navigational purposes, especially for transferring the bearing of a plotted course to a compass rose.

Origin of parallel rulers

First recorded in 1695–1705

British Dictionary definitions for parallel ruler

parallel ruler

noun

engineering a drawing instrument in which two parallel edges are connected so that they remain parallel, although the distance between them can be varied