Webster's Revised Unabridged Dictionary · 1913

Monoceros

Monoceros , noun

[Latin, from Greek {not transcribed}; mo`nos alone, single + ke`ras horn.]

1.
A one-horned creature; a unicorn; a sea monster with one horn.
Mighty monoceroses with immeasured tails. — Spenser
2.
(Astronomy) The Unicorn, a constellation situated to the east Orion.