Shac·kle, n.
 1. Something which confines the legs or arms so as to prevent their free motion; specifically, a ring or band inclosing the ankle or wrist, and fastened to a similar shackle on the other leg or arm, or to something else, by a chain or a strap; a gyve; a fetter.
    His shackles empty left; himself escaped clean.   --Spenser.
 2. Hence, that which checks or prevents free action.
    His very will seems to be in bonds and shackles.   --South.
 3. A fetterlike band worn as an ornament.
    Most of the men and women . . . had all earrings made of gold, and gold shackles about their legs and arms.   --Dampier.
 4. A link or loop, as in a chain, fitted with a movable bolt, so that the parts can be separated, or the loop removed; a clevis.
 5. A link for connecting railroad cars; -- called also drawlink, draglink, etc.
 6. The hinged and curved bar of a padlock, by which it is hung to the staple.
 Shackle joint Anat., a joint formed by a bony ring passing through a hole in a bone, as at the bases of spines in some fishes.