protractor

American  

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

noun

1. a person or thing that protracts.

2. (in surveying, mathematics, etc.) an instrument having a graduated arc for plotting or measuring angles.

3. Anatomy. a muscle that causes a part to protrude.

---

protractor British  

/ prəˈtræktə /

noun

1. an instrument for measuring or drawing angles on paper, usually a flat semicircular transparent plastic sheet graduated in degrees

2. a person or thing that protracts

3. a surgical instrument for removing a bullet from the body

4. anatomy a former term for extensor

---

Etymology

Origin of protractor

From Medieval Latin, dating back to 1605–15; protract, -tor

Example Sentences

I taught them how to use rulers, compasses, protractors, and triangular scales.

From Literature

These include the earliest dated set of European navigation instruments found thus far: compasses, protractors, calipers, sounding leads, tide calculators, and a device for calculating speed called a log reel.

From Literature

The head coach gets a warning, I mean that normally - I don’t know, I didn’t have a protractor out there.

From Washington Times

His fingers, unlike Baba’s, were clumsy around tools, especially ones as delicate as a protractor, compass, or ruler.

From Literature

I learned the ritual that very first summer with my firstborn, when the August air was still heavy but the Target was suddenly full of pens and protractors.

From Salon