protractor

noun

Etymology: Etymology tree English protract English -or English protractor From protract + -or.

1. One who, or that which, protracts, or causes protraction.
2. A circular or semicircular tool for drawing or measuring angles.

   “Use a protractor to measure the angle accurately.”

   “The student forgot to bring her protractor to geometry class.”

3. An instrument formerly used in extracting foreign or offensive matter from a wound.
4. A muscle that extends an organ or part; opposed to retractor.
5. An adjustable pattern used by tailors.