Cleavers are a little like handaxes, they are large and oblong or U-shaped tools meant to be held in the hand but unlike handaxes, they have a wide, straight cutting edge running at right angles to the axis of the tool.
Acheulean cleavers resemble handaxes but with the pointed end truncated away. Flake cleavers have a cutting edge created by a tranchet flake being struck from the primary surface.