rigol

noun3

1. •
   A ridge or channel above a porthole to redirect water flow from dripping inside the vessel.
2. •
   (no longer used) A diadem, crown (ornamental headband worn as a badge of royalty).

   • […] this is a sleep That from this golden rigol hath divorc’d So many English kings. — 1596
3. •
   (no longer used) A circle.

   • About the mourning and congealed face Of that black blood a watery rigol goes, Which seems to weep upon the tainted place: — 1594