Pronunciation: (prō-trak'tur, pru-), [key]
1. a person or thing that protracts.
2. (in surveying, mathematics, etc.) an instrument having a graduated arc for plotting or measuring angles.
3. Anat.a muscle that causes a part to protrude.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.