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) opacity of the cornea
WordReference Random House Learner's Dictionary of American English © 2025
neb•u•la /ˈnɛbyələ/USA pronunciation
n. [countable], pl. -lae /-ˌli, -ˌlaɪ/USA pronunciation -las.
WordReference Random House Unabridged Dictionary of American English © 2025- Astronomya cloud of gas and dust in outer space between stars.
neb•u•la
(neb′yə lə),USA pronunciation n., pl. -lae (-lē′, -lī′),USA pronunciation -las.
neb′u•lar, adj.
- Astronomy
- AstronomyAlso called diffuse nebula. a cloud of interstellar gas and dust. Cf. dark nebula, emission nebula, reflection nebula.
- (formerly) any celestial object that appears nebulous, hazy, or fuzzy, and extended in a telescope view.
- Pathology
- a faint opacity in the cornea.
- cloudiness in the urine.
- Drugsany liquid medication prepared for use as a spray.
- Latin: a mist, vapor, cloud; akin to Greek nephélē cloud, German Nebel fog, haze
- 1655–65
Collins Concise English Dictionary © HarperCollins Publishers::
'nebula' also found in these entries (note: many are not synonyms or translations):
Coalsack
- Crab Nebula
- Dumbbell nebula
- Eta Carinae
- Great Nebula of Orion
- Horsehead Nebula
- Niflheim
- Orion
- Orion Nebula
- Ring Nebula
- Taurus
- absorption nebula
- cosmic dust
- crab
- dark nebula
- diffuse nebula
- emission nebula
- extragalactic nebula
- galactic nebula
- globule
- isophote
- nebulated
- nebulose
- nebulosity
- nebulous
- nephelometer
- nepho-
- nimbus
- planetary nebula
- reflection nebula
- spiral nebula
- supernova