Knurl /(nûrl)/

Knurl

n.
  1. A contorted knot in wood; a crossgrained protuberance; a nodule; a boss or projection.
  2. One who, or that which, is crossgrained.

Knurl

v. t.
  1. To provide with ridges, to assist the grasp, as in the edge of a flat knob, or coin; to mill.