noun: A kind of purchase for hoisting or lowering a cylindrical burden, as a cask. The middle of a long rope is fastened aloft, and both ends of the rope are looped under, then over the cylinder and looped back towards the attachment point. The object rests in the loops, and rolls upward in them as the rope ends are hauled up, or downward when the ends are payed out.
noun: A double sling made of a single rope, for slinging a cask, gun, etc.
