(1):

(n.) One who, or that which, protracts, or causes protraction.

(2):

(n.) A mathematical instrument for laying down and measuring angles on paper, used in drawing or in plotting. It is of various forms, semicircular, rectangular, or circular.

(3):

(n.) An instrument formerly used in extracting foreign or offensive matter from a wound.

(4):

(n.) A muscle which extends an organ or part; - opposed to retractor.

(5):

(n.) An adjustable pattern used by tailors.