In sailing, the clew is the lower aft corner of the sail. The clew of a jib is the free corner (not attached to any standing rigging), to which port and starboard jib sheets are attached to control the angle of the sail to the wind. In a sail with a boom (such as a mainsail on a sloop), the clew is attached to the boom, and can often be tightened along the boom using the outhaul to adjust the sail shape. On a square sail or a symmetrical spinnaker, both lower corners are called clews, but the corner to which the sheet, working sheet or leeward sheet is currently attached is called the clew.
