Hydrus

noun

astronomy

: a small southern constellation that is visible between the constellations of Tucana and Mensa and that is represented by the figure of a snake

… a small constellation in the southern sky called Hydrus, which means "male water snake."

—Jesse Eisinger and Jake Bernstein, Knoxville (Tennessee) News-Sentinel, 18 Apr. 2010

Word History

First Known Use

1675, in the meaning defined above

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

• More than 250,000 words that aren't in our free dictionary
• Expanded definitions, etymologies, and usage notes
• Advanced search features
• Ad free!