[ proh-trak-ter, pruh- ]
/ proʊˈtræk tər, prə- /


a person or thing that protracts.
(in surveying, mathematics, etc.) an instrument having a graduated arc for plotting or measuring angles.
Anatomy. a muscle that causes a part to protrude.

Origin of protractor

From Medieval Latin, dating back to 1605–15; see origin at protract, -tor Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for protractor

British Dictionary definitions for protractor


/ (prəˈtræktə) /


an instrument for measuring or drawing angles on paper, usually a flat semicircular transparent plastic sheet graduated in degrees
a person or thing that protracts
a surgical instrument for removing a bullet from the body
anatomy a former term for extensor
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medicine definitions for protractor


[ prō-trăktər ]


A muscle that extends a limb or other part.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.