Dictionary.com
Thesaurus.com
Synonyms
Trivia Time
If an idea seems nebulous, what is it lacking?

nebulous

American  
[neb-yuh-luhs] / ˈnɛb jə ləs /

adjective

  1. hazy, vague, indistinct, or confused.

    a nebulous recollection of the meeting; a nebulous distinction between pride and conceit.

  2. cloudy or cloudlike.

  3. of or resembling a nebula or nebulae in deep space; nebular.


nebulous British  
/ ˈnɛbjʊləs /

adjective

  1. lacking definite form, shape, or content; vague or amorphous

    nebulous reasons

  2. of, characteristic of, or resembling a nebula

  3. rare misty or hazy

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms


Etymology

Origin of nebulous

First recorded in 1375–1425; late Middle English, from Latin nebulōsus “full of mist, foggy, cloudy,” from nebul(a) “cloud, mist, vapor” ( see nebula) + -ōsus -ous


Explanation

Something that's nebulous is clouded or hazy. When you walk through the woods on a foggy morning, the trees may all have a mysterious, nebulous look to them. When you fly in a plane on an overcast day, the land below you looks nebulous and indistinct. You can also use nebulous in a more figurative way, to describe vague ideas or fuzzy concepts. Nebulous comes from the Latin nebulosus, "cloudy, misty, or foggy." Its root is nebula, which is "vapor or fog" in Latin and was adopted by astronomers in the 1700s to mean "a cloud of gas and dust in outer space."

Keep Reading on Vocabulary.com

Vocabulary lists containing nebulous

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

“But songwriting is so much more nebulous, so much harder to sue.”

From Los Angeles Times ● Sep. 21, 2026

“These nebulous and overtly conjectural allegations do not come close to knitting Ganieva, Harris, and Rubenstein together in any solid or coherent way in concerted acts towards a common end,” the judge wrote.

From The Wall Street Journal ● Aug. 29, 2026

Most people react in similarly positive ways, expressing empathy or, my personal favorite, commiserating with me over their own nebulous medical conditions.

From Slate ● May 23, 2026

"Once again, the nebulous Boko Haram terrorist group carried out a cowardly attack last night on our military base at Barka Tolorom," Chadian President Mahamat Idriss Deby Itno said on Tuesday in a Facebook post.

From Barron's ● May 5, 2026

Daniel lives in the nebulous space in between.

From "The Sun Is Also a Star" by Nicola Yoon

Random Word

Spin the wheel and learn a new word!

Get a word


Vocabulary.com logo
by dictionary.com

Join 14,000,000 vocabulary learners

Start learning new words today on VocabTrainer.
You'll remember them forever.

Start training