A metal fastening, usually one of a pair, for encircling and confining the ankle or wrist of a prisoner or captive. The prisoner was led away in shackles, his hands bound tightly.
A restraint or impediment to free action, progress, or expression. The new regulations acted as a shackle on the company's growth.
A U-shaped metal piece with a pin or bolt across the opening, used to secure a chain or rope to something. The sailor used a shackle to attach the anchor to the boat.
A length of anchor chain equal to 15 fathoms (approximately 90 feet), used as a unit of measurement at sea. The chart shows the anchor resting in three shackles of water.