Definition of Mira
: a variable binary star system that is seen in the constellation Cetus To see a star that varies intrinsically in brightness, we have to wait until late summer and fall. Mira, in the constellation Cetus the Whale, is the sky's best slowly varying red giant. Mira climbs from invisibility (at 9th magnitude) to 4th magnitude and then fades again roughly every 330 days. — Alister Ling, Astronomy, January 1992 —called also Omicron Ceti ◆The star that we see when look at Mira is a variable red giant, the brightest of a binary pair of variable stars, and was one of the first variable stars identified by astronomers.
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.
Join MWU now and get access to America’s largest dictionary, with:
- 300,000 words that aren't in our free dictionary
- Expanded definitions, etymologies, and usage notes
- Advanced search features
- Ad free!
First Known Use of mira
Learn More about mira
Spanish Central: Translation of Mira
Seen and Heard
What made you want to look up Mira? Please tell us where you read or heard it (including the quote, if possible).