Pronunciation: (ri-trak'tur),[key] —n. 1. a person or thing that retracts.
2. Anat.a muscle that retracts an organ or protruded part.
3. Surg.an instrument or appliance for drawing back an impeding part, as the edge of an incision.
4. a mechanism, device, or the like that regulates retraction: to adjust the retractor on a seat belt.