An old ship used as a prison. Large, redundant old battle ships without their masts were used as floating prisons for captives who were sentenced to be transported to British overseas penal colonies. Hulks were moored along the River Thames at Chatham, Deptford, Woolwich and Sheerness, usually near dockyards or arsenals so that prisoners could be used there as labourers.

A ship without masts or rigging; also a vessel to remove masts into or out of ships by means of sheers, from whence they are called sheer hulks.

Generally, an unrigged hull condemned as unfit for the risks of the sea and used as a floating depot or crane platform in a harbor or roadstead.

a ship that has been wrecked and abandoned

a sailing ship, no longer fit to go to sea, which was stripped of its masts and used as a floating prison

A hulk is a ship that is afloat, but incapable of going to sea. Although sometimes used to describe a ship that has been launched but not completed, it most often refers to an old ship that has had its rigging and/or internal equipment removed, retaining only its flotational qualities.