An instrument for copying a plane figure to a desired scale, consisting of styluses for tracing and copying mounted on four jointed rods in the form of a parallelogram with extended sides.
A similarly jointed framework, such as a power-collecting trolley on an electric locomotive or an extensible telephone arm.
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.