nebula

noun

neb·​u·​la ˈne-byə-lə 

plural nebulae ˈne-byə-ˌlē  -ˌlī  also nebulas

1

: any of numerous clouds of gas or dust in interstellar space

2

: galaxy sense 1b

especially : a galaxy other than the Milky Way galaxy

—not used technically

nebular

ˈne-byə-lər 

adjective

Did you know?

The history of nebula belongs not to the mists of time but to the mists of Latin: in that language nebula means "mist" or "cloud." In its earliest English uses in the 1600s, nebula was chiefly a medical term that could refer either to a cloudy formation in urine or to a cloudy speck or film on the eye. Nebula was first applied to great interstellar clouds of gas and dust in the early 1700s. The adjective nebulous comes from the same Latin root as nebula, and it is considerably older, being first used as a synonym of cloudy or foggy as early as the 1300s. Like nebula, this adjective was not used in an astronomical sense until centuries later.

Examples of nebula in a Sentence

Recent Examples on the Web

The twisting nebula seen in van Zuilen's image is just one section of the sprawling 120-light-year-wide supernova remnant, which can be found close to the bright star Epsilon Cygni in the constellation Cygnus along the glowing band of the Milky Way in November. —Anthony Wood, Space.com, 17 Nov. 2025

Astronomer Heber Curtis noted that the Andromeda Nebula—one of the most famous of these spiral nebulas, easily seen by the naked eye in dark skies—hosted several novae. —Phil Plait, Scientific American, 13 Nov. 2025

As if amid a crystal nebula, the blues take on swirling hues of purple and silver. —Greyson Ferguson, Travel + Leisure, 5 Nov. 2025

August has been a month jam-packed with cosmic phenomena visible from Earth – from nebulas to meteor showers to planetary conjunctions. —Eric Lagatta, USA Today, 20 Aug. 2025

Word History

Etymology

New Latin, from Latin, mist, cloud; akin to Old High German nebul fog, Greek nephelē, nephos cloud

First Known Use

1718, in the meaning defined at sense 1

Phrases Containing nebula

• planetary nebula

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Kids Definition

nebula

noun

neb·​u·​la ˈneb-yə-lə 

plural nebulas or nebulae -ˌlē 

-ˌlī

1

: any of many huge clouds of gas or dust in deep space

2

: galaxy sense 2

nebular

-lər 

adjective

Medical Definition

nebula

noun

neb·​u·​la ˈneb-yə-lə 

plural nebulas or nebulae -ˌlē  -ˌlī 

: a slight cloudy opacity of the cornea