nebulous

adjective

neb·​u·​lous ˈne-byə-ləs How to pronounce nebulous (audio)
1
: of, relating to, or resembling a nebula : nebular
2
: indistinct, vague
… this nebulous thing called jazz.Josef Woodard
… the nebulous region between mere suspicion and probable causeW. R. LaFave & J. H. Israel
The plan is too nebulous.
nebulously adverb
nebulousness noun

Did you know?

Nebulous may sound otherworldly—after all, it’s related to nebula, which refers to an interstellar cloud of gas or dust—but its mysteriousness is rooted in more earthly unknowns. Both words ultimately come from Latin nebula, meaning “mist, cloud,” and as far back as the 14th century nebulous could mean simply “cloudy” or “foggy.” Nebulous has since the late 17th century been the adjective correlating to nebula (as in “nebulous gas”), but the word is more familiar in its figurative use, where it describes things that are indistinct or vague, as when Teju Cole wrote of an avant-garde photographer who viewed photography as existing “neither in the camera nor in the printed photograph, but in a more nebulous zone.”

Examples of nebulous in a Sentence

These philosophical concepts can be nebulous. made nebulous references to some major changes the future may hold
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The James Webb Space Telescope (JWST) caught the two jets slamming into the interstellar medium around them, forming the nebulous structure known as Sharpless 2-284, or Sh2-284 for short. Keith Cooper, Space.com, 11 Sep. 2025 Which method is better depends on whether your business has more nebulous or strict departments. John Brandon, PC Magazine, 9 Sep. 2025 Indeed, authenticity is a nebulous, shape-shifting concept. Tomas Chamorro-Premuzic, Forbes.com, 9 Sep. 2025 This nebulous term would only add to the games some departments play to avoid disclosing records. Charles Champion, Oc Register, 8 Sep. 2025 See All Example Sentences for nebulous

Word History

Etymology

Latin nebulosus misty, from nebula

First Known Use

1674, in the meaning defined at sense 1

Time Traveler
The first known use of nebulous was in 1674

Browse Nearby Words

Podcast

Cite this Entry

“Nebulous.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/nebulous. Accessed 15 Sep. 2025.

Kids Definition

nebulous

adjective
neb·​u·​lous ˈneb-yə-ləs How to pronounce nebulous (audio)
1
: of, relating to, or resembling a nebula
2
: not clear or sharp : vague
nebulously adverb
nebulousness noun

More from Merriam-Webster on nebulous

Last Updated: - Updated example sentences
Love words? Need even more definitions?

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