Definition of nebula in English:


Line breaks: neb¦ula
Pronunciation: /ˈnɛbjʊlə

noun (plural nebulae /-liː/ or nebulas)

  • 1 Astronomy A cloud of gas and dust in outer space, visible in the night sky either as an indistinct bright patch or as a dark silhouette against other luminous matter.
    More example sentences
    • Evolutionists believe that the solar system condensed out of a cloud of gas and dust called a nebula, hence the nebular hypothesis.
    • We have missions that include active nebulas, swirling dust clouds, moving asteroids and asteroid fields.
    • A planetary nebula forms when Sun-like stars gently eject their outer gaseous layers to form bright nebulae with amazing twisted shapes.
  • 1.1 dated A galaxy.
    More example sentences
    • Then Edward Hubble discovered that the nebulae were other galaxies like ours only much further away than was thought possible.
    • In further studies, he showed that these nebulas are actually other galaxies, and he went on to classify them.
    • Hubble realized that these spiral nebulae were so far away they were actually galaxies - separate cities of stars - far beyond our own Milky Way.
  • 2 Medicine A clouded spot on the cornea causing defective vision.
    More example sentences
    • The bruise over his eye had settled in to a purple nearly matching the nebula itself, but the swelling had reduced dramatically.
    • It treats conjunctivitis, pterygium, nebula and pain in the eyes.


mid 17th century (as a medical term): from Latin, literally 'mist'.

More definitions of nebula

Definition of nebula in:

Get more from Oxford Dictionaries

Subscribe to remove adverts and access premium resources

Word of the day coloratura
Pronunciation: ˌkɒlərəˈtjʊərə
elaborate ornamentation of a vocal melody