nebulous
Americanadjective
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hazy, vague, indistinct, or confused.
a nebulous recollection of the meeting; a nebulous distinction between pride and conceit.
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cloudy or cloudlike.
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of or resembling a nebula or nebulae in deep space; nebular.
adjective
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lacking definite form, shape, or content; vague or amorphous
nebulous reasons
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of, characteristic of, or resembling a nebula
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rare misty or hazy
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."
Vocabulary lists containing nebulous
To Kill a Mockingbird
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The Great Gatsby
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1984
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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.
“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
A sippable sweet treat: Refreshers—a nebulous class of drinks similar to lemonade or smoothies—are taking over menus from Starbucks to McDonald’s.
From Slate ● Aug. 14, 2026
Ohtani’s timeline back to the mound is nebulous at this point.
From Los Angeles Times ● Aug. 6, 2026
The average country listener wants to have their past misremembered for them, whether it’s the Judds asking Grandpa about the good old days or Tim McGraw missing the nebulous “back when.”
From Salon ● Aug. 3, 2026
Garrett watched a mist drift by, whispering and whispering, shaped like a beautiful and nebulous woman.
From "The Martian Chronicles" by Ray Bradbury
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
