The Collaborative International Dictionary of English v.0.48:

Nur \Nur\, n. [Cf. Knur.]
   A hard knot in wood; also, a hard knob of wood used by boys
   in playing hockey.
   [1913 Webster]

         I think I'm as hard as a nur, and as tough as
         whitleather.                             --W. Howitt.
   [1913 Webster] Nuraghe