ROWEL

noun a little flat ring or wheel on horses' bits.

2. rowel ·noun the little wheel of a spur, with sharp points.

3. rowel ·vt to insert a rowel, or roll of hair or silk, into (as the flesh of a horse).

4. rowel ·noun a roll of hair, silk, ·etc., passed through the flesh of horses, answering to a seton in human surgery.