protractor

noun

pro·​trac·​tor prō-ˈtrak-tər 

prə-

1

a

: one that protracts

b

: a muscle that extends a part

2

: an instrument for laying down and measuring angles in drawing and plotting

Examples of protractor in a Sentence

Recent Examples on the Web

This useful multitool fits on any keychain but has a staggering 16 different functions, including screw driver, protractor, ruler, bottle opener, and bike spoke key. —Malia Griggs, Glamour, 11 Oct. 2024

The team is combing the soil to find any bone fragments, as well as personal items such as uniforms, navigation protractors, watches and rings. —Stephen Smith, CBS News, 21 May 2024

The spiral pictured is 120 feet (36.5 meters) wide, photographed by drone, and was plotted out on the ground using a protractor specially fabricated for the occasion by the band with a pivoting centre and 60ft long adjustable arm. —Evan Minsker, Pitchfork, 19 Jan. 2024

But the crew might have to calculate the target’s coordinates using a map and protractor. —David Axe, Forbes, 21 Mar. 2023

Word History

Etymology

probably borrowed from Medieval Latin prōtractor "instrument for measuring angles," from Latin prōtrac-, variant stem of prōtrahere "to drag forward, draw or pull out, bring into the open" + -tor, agent suffix — more at protract

Note: The word occurs at least once in printed versions of the Peri optikēs (known as the Perspectiva) of Vitellio/Witelo, the first of which appeared in Nuremberg in 1535. Witelo, taken to be ethnically Polish, was a natural scientist and philosopher born in Silesia in the thirteenth century.

First Known Use

1588, in the meaning defined at sense 2

Kids Definition

protractor

noun

pro·​trac·​tor prō-ˈtrak-tər 

: an instrument for drawing and measuring angles

Medical Definition

protractor

noun

pro·​trac·​tor -tər 

: a muscle that extends a part compare retractor sense b