Webster’s New World College Dictionary noun a wheel with a rim notched into teeth, which mesh with those of another wheel or of a rack to transmit or receive motion
Webster’s New World College Dictionary, Fourth Edition, compiled by the
editors of Webster’s New World Dictionaries. Copyright © 2010 by Houghton
Mifflin Harcourt. Published by Houghton Mifflin Harcourt. All rights reserved.