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

Curtis argued that the spiral nebulas were galaxies in their own right, but said that the Milky Way was only 10,000 light years across. —Keith Cooper, Space.com, 17 Jan. 2025

The research team compared the model with archival telescope observations of its nebula — the giant cloud of gas and dust, visible to this day, that is the remnant of the monumental event. —Jacopo Prisco, CNN, 13 Aug. 2024

Related: Best telescopes: Observe stars, galaxies, nebulas, planets and more March 29: Partial eclipse of the sun — The dark shadow cone of the moon, from where a total solar eclipse can be seen, will completely miss Earth, passing approximately 180 miles (290 kilometers) above the North Pole. —Joe Rao, Space.com, 31 Dec. 2024

This close-up of the nebula was featured on NASA's image of the day series, and was shot using a narrowband, and projected with the elements of sulfur, hydrogen and oxygen. —Space.com Staff, Space.com, 1 Jan. 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