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

Nearly every sound lingers like an unanswered question, and the scant bass drums that appear in most tracks are less for keeping time than providing anchor points in an inestimable nebula. —Dash Lewis, Pitchfork, 29 Jan. 2026

The portability makes binoculars an ideal entry point for skywatching, while their light-gathering ability helps tease out the faint glow of star clusters, nebulas and even some galaxies. —Anthony Wood, Space.com, 28 Jan. 2026

But the appearance of planetary nebulas has little to do with planets at all—these nebulas are actually roiling clouds of hot gas that emanate from dying sunlike stars and linger after their deaths. —Joseph Howlett, Scientific American, 20 Jan. 2026

Right in the middle of the nebula was a clear, narrow strip glowing strongly in the light emitted by ionized iron atoms. —Rupendra Brahambhatt, Interesting Engineering, 18 Jan. 2026

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