(1):

(n.) The act of retracting, or drawing back; the state of being retracted; as, the retraction of a cat's claws.

(2):

(n.) The act of withdrawing something advanced, stated, claimed, or done; declaration of change of opinion; recantation.

(3):

(n.) The act of retracting or shortening; as, the retraction of a severed muscle; the retraction of a sinew.

(4):

(n.) The state or condition of a part when drawn back, or towards the center of the body.