The Collaborative International Dictionary of English v.0.48:

Rowel \Row"el\, v. t. [imp. & p. p. Roweledor Rowelled; p.
   pr. & vb. n. Roweling or Rowelling.] (Far.)
   To insert a rowel, or roll of hair or silk, into (as the
   flesh of a horse). --Mortimer.
   [1913 Webster]