monoceros

1 of 2

noun (1)

mo·​noc·​er·​os mə-ˈnä-sə-rəs 

plural -es

1

obsolete : one-horned rhinoceros

2

: a fish (as the swordfish or sawfish) with one hornlike process

Monoceros

2 of 2

noun (2)

Mo·​noc·​er·​os mə-ˈnä-sə-rəs 

astronomy

: a northern constellation that is visible between the constellations of Canis Minor and Canis Major and that is represented by the figure of a unicorn

Betelgeuse, Sirius and Procyon form an almost perfect equilateral triangle. Most of the constellation Monoceros lies in that triangle. Unless you're observing away from city lights, you probably won't see much with your naked eye. And, even from a dark site, faint Monoceros looks nothing like a unicorn.

—John Stanley, Arizona Republic, 26 Mar. 2005

Word History

Etymology

Noun (1)

Middle English, from Middle French, from Latin, from Greek monokeros, from mon- + -keros (from keras horn)

First Known Use

Noun (2)

1715, in the meaning defined above

The Ultimate Dictionary Awaits

Expand your vocabulary and dive deeper into language with Merriam-Webster Unabridged.

1. Expanded definitions
2. Detailed etymologies
3. Advanced search tools
4. All ad-free

Discover what makes Merriam-Webster Unabridged the essential choice for true word lovers.

Start Your Free Trial Now