Dei·​mos ˈdē-ˌmōs How to pronounce Deimos (audio)
: the smaller and outermost of the two satellites of Mars with an irregular shape and a diameter of approximately 9 miles (15 km)
Other small bodies in the solar system may be asteroids. Phobos and Deimos, the two satellites of Mars, the eight outer moons of Jupiter and the Saturnian satellite Phoebe appear to be captured asteroids.Richard P. Binzel et al., Scientific American, October 1991

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!

Dictionary Entries Near Deimos

Cite this Entry

“Deimos.” Dictionary, Merriam-Webster, Accessed 22 Apr. 2024.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!