What's the noun for lapper? Here's the word you're looking for.
lap
The act or process of lapping.
That part of any substance or fixture which extends over, or lies upon, or by the side of, a part of another.
The state or condition of being in part extended over or by the side of something else; or the extent of the overlapping.
The amount by which a slide valve at its half stroke overlaps a port in the seat, being equal to the distance the valve must move from its mid stroke position in order to begin to open the port. Used alone, lap refers to outside lap (see below).
(sports) One circuit around a race track, or one traversal down and then back the length of a pool
In card playing and other games, the points won in excess of the number necessary to complete a game; — so called when they are counted in the score of the following game.
A sheet, layer, or bat, of cotton fiber prepared for the carding machine.
A piece of brass, lead, or other soft metal, used to hold a cutting or polishing powder in cutting glass, gems, etc. or in polishing cutlery, etc. It is usually in the form of a wheel or disk that revolves on a vertical axis.
(music) Lengths of fine wire, silver, gold, silk or whalebone wrapped tightly around the bow stick adjacent to the leather part of the bow grip at the heel of the bow.
“Others will upheave the blacksmith's hammer, or drive the plane over the carpenter's bench, or take the lapstone and the awl and learn the trade of shoemaking.”
“The convictions resulted from a Police Scotland covert operation, Operation Lapstone, led by the Organised Crime and Counter Terrorism Unit.”
“One giant block of rock on the floor of the dene, called the Devil's Lapstone, is a chunk of reef limestone which fell from the steep sides.”