Definition of slotter:
(n) :
(agent noun) Someone or something that slots (that is, makes slots).
(n) :
(engineering, manufacturing) A tool used to make a mortise, or to shape the sides of an aperture.
(n) :
(engineering, manufacturing) Such a tool that is much like a shaper but with a smaller ram, vertically mounted.
(v) :
(transitive) To make filthy; to foul.
(n) :
Filth.