nebula

American  

[neb-yuh-luh] / ˈnɛb jə lə /

noun

• nebulae,
  plural
• nebulas
  plural

1. Astronomy.

   1. Also called diffuse nebula.  a cloud of interstellar gas and dust.

   2. (formerly) any celestial object that appears nebulous, hazy, or fuzzy, and extended in a telescope view.

2. Pathology.

   1. a faint opacity in the cornea.

   2. cloudiness in the urine.

3. any liquid medication prepared for use as a spray.

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nebula British  

/ ˈnɛbjʊlə /

noun

1. astronomy a diffuse cloud of particles and gases (mainly hydrogen) that is visible either as a hazy patch of light (either an emission or a reflection nebula ) or an irregular dark region against a brighter background ( dark nebula ) Compare planetary nebula

2. pathol

   1. opacity of the cornea

   2. cloudiness of the urine

3. any substance for use in an atomizer spray

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nebula Scientific  

/ nĕb′yə-lə /

• nebulae
  plural

1. A visible, thinly spread cloud of interstellar gas and dust. Some nebulae are the remnants of a supernova explosion, others are gravity-induced condensations of the gases in the interstellar medium which in certain cases may become a site for the formation of new stars. The term was formerly used of any hazy, seemingly cloudlike object, including what are now recognized as other galaxies beyond the Milky Way; it is restricted now to actual clouds of gas and dust within our own galaxy.

2. ◆ Nebulae are generally classified as bright or dark. Among the bright nebulae are cold clouds that reflect light from nearby stars (reflection nebulae) and hot, ionized clouds that glow with their own light (emission nebulae). Dark nebulae—cold clouds that absorb the passing light from background stars—are called absorption nebulae.

3. See more at star

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nebula Cultural  

1. plur. nebulae In astronomy, a hazy patch of light visible in the sky. Some nebulae are clouds of gas within the Milky Way; others are distant galaxies.

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Other Word Forms

Derived Forms

• nebular
  adjective
• nonnebular
  adjective
• prenebular
  adjective

Inflected Forms

Nouns

• nebulae
  plural
• nebulas
  plural

Etymology

Origin of nebula

First recorded in 1655–65; from Latin: “cloud, mist, vapor”; akin to German Nebel “fog, haze,” Greek nephélē “cloud,” Sanskrit nábha- “cloud, vapor”

Explanation

A nebula is a massive cloud of gas and dust in outer space. A nebula is sometimes the birthplace of stars, such as the Orion Nebula where new stars — a youthful million years old — are still forming. Another example of a nebula is the Crab Nebula — the glowing result of a supernova, noted by Chinese astronomers in 1054 CE. It spans about 10 light-years in length. In biology, a nebula may be a cloudy formation in the eye, or a cloudiness of urine. It also refers to a medicinal preparation put in a nebulizer. When you are talking about more than one nebula (which is probably not that often for the average person), say nebulae.

Example Sentences

See Examples For:

nebula nebulae nebulas

Wallace said he had always been a keen photographer and had been on a learning curve with the tech involved in capturing outer space, including galaxies and nebula.

From BBC ● Aug. 13, 2026

The James Webb Space Telescope has captured new images of NGC 2392, a planetary nebula commonly known as the Lion Nebula, revealing the cosmic object in striking infrared detail.

From Science Daily ● Aug. 12, 2026

The Hubble Space Telescope previously observed the nebula in 2000, imaging the lion face-shaped target in visible light.

From Science Daily ● Aug. 12, 2026

In the lion-shaped appearance of the nebula, this stellar remnant resembles a small button nose.

From Science Daily ● Aug. 12, 2026

A Level Three Awkward Silence began to coalesce around us, like interstellar hydrogen pulled together by gravity to form a new nebula.

From "Darius the Great Is Not Okay" by Adib Khorram

As the hot core becomes exposed, it emits intense radiation that energizes the surrounding gas, producing the glowing shells seen in planetary nebulae such as the Helix, Stingray, and Butterfly nebulae.

From Science Daily ● Feb. 13, 2026

These glowing structures form two long, narrow nebulae driven by intense activity around a supermassive black hole at the galaxy's core.

From Science Daily ● Jan. 10, 2026

That’s why such nebulae are often called stellar nurseries.

From Space Scoop ● Oct. 31, 2025

Shapley argued that the spiral nebulae were small and in the Milky Way, while Curtis took a more radical position that they were independent galaxies, extremely large and distant.

From Salon ● Feb. 14, 2025

Squinting, I could also make out a few tiny nebulae and galaxies in the distance.

From "Ready Player One: A Novel" by Ernest Cline

First observed in the early 1800s, the Helix Nebula has become one of the most recognizable planetary nebulas in the sky thanks to its bold, ring-like appearance.

From Science Daily ● Jan. 26, 2026

That they do through Jeff Russo's opening theme, which incorporates notes from the original series' melody with dreamy images of prismatic colored nebulas, jewel-like asteroid belts, and other mesmerizing sights along the Enterprise's cruising path.

From Salon ● Dec. 29, 2022

Gorgeous photographs of swirling galaxies, fiery nebulas and newborn stars stunned the world.

From Scientific American ● Dec. 1, 2022

In July, the Webb, the largest-ever space telescope, enthralled both scientists and the public with spectacular glimpses of never-before-seen nebulas, exoplanets, ancient galaxies, and fluffy translucent clouds of space dust swirling around shimmering stars.

From New York Times ● Oct. 13, 2022

I was rocketing through space, flying past exploding nebulas.

From "Klawde: Evil Alien Warlord Cat" by Johnny Marciano and Emily Chenoweth