castoreum

noun2

1. •
   The bitter exudate of the castor sacs of mature beavers, used as a scent mark, and as a tincture in some perfumes.

   • While the role of castoreum as a means of territorial advertisement has been extensively investigated and supported, the possibility of coding for sex information has not yet been excluded. — 1999
2. •
   (no longer used) A hat made from beaver fur.