Source : Webster's Revised Unabridged Dictionary (1913)

Knurl \Knurl\, n. [See {Knar}, {Gnar}.]
   A contorted knot in wood; a crossgrained protuberance; a
   nodule; a boss or projection.

   2. One who, or that which, is crossgrained.

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