n. The bitter exudate from the castor sacs of mature beavers
the GNU version of the Collaborative International Dictionary of English
n. A peculiar bitter orange-brown substance, with strong, penetrating odor, found in two sacs between the anus and external genitals of the beaver; castor; -- used in medicine as an antispasmodic, and by perfumers.
The Century Dictionary and Cyclopedia
n. Same as castor.
Word Usage
"The scent is leathery and animalic think both indolic and uric at once, and with that dry leathery undertone – hence it is most commonly described as a cross between civet and castoreum, which is a pretty good description if you ask me."