American Dictionary of the English Language

U'NICORN, noun [Latin unicornis; unus, one, and cornu, horn.]

1. an animal with one horn; the monoceros. this name is often applied to the rhinoceros.

2. The sea unicorn is a fish of the whale kind, called narwal, remarkable for a horn growing out at his nose.

3. A fowl.

fossil unicorn or fossil unicorn's horn, a substance used in medicine, a terrene crustaceous spar.