Retractor

noun

1. One who, or that which, retracts.
2. In breech-loading firearms, a device for withdrawing a cartridge shell from the barrel.
3. A chess puzzle in which a number of moves are retracted and the solver is challenged to reach an alternate outcome.
4. A surgical instrument used to hold apart the edges of an incision or wound.
5. A bandage to protect soft parts of the body from injury by a surgical saw.