neb·​u·​lous ˈne-byə-ləs How to pronounce nebulous (audio)
: of, relating to, or resembling a nebula : nebular
: 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 other-worldly—after all, it’s related to nebula, which refers to a distant galaxy or 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 Jack London wrote of “ideas that were nebulous at best and that in reality were remembered sensations.”

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 Some weeks that deadline looms large, arrives way too fast and the topic nebulous at best. Rita Nader Heikenfeld, The Enquirer, 13 Apr. 2024 Ink is a nebulous material, Little explained in a phone call, made from nearly anything rich in pigments along with the binder gum Arabic. Jacqui Palumbo, CNN, 28 Mar. 2024 See all Example Sentences for nebulous 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'nebulous.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


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


Dictionary Entries Near nebulous

Cite this Entry

“Nebulous.” Dictionary, Merriam-Webster, Accessed 23 Apr. 2024.

Kids Definition


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

More from Merriam-Webster on nebulous

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