SHEAVE n.
A wheel having a groove in the rim for a rope to work in, and set in a block, mast, or the like; the wheel of a pulley. Sheave hole, a channel cut in a mast, yard, rail, or other timber, in which to fix a sheave.
SKID n. 2 definitions
A shoe or clog, as of iron, attached to a chain, and placed under the wheel of a wagon to prevent its turning when descending a steep hill; a drag; a skidpan; also, by extension, a hook attached to a chain, and used for the same purpose.