nebula
/ˈnɛb.jə.lə/ noun
Forms nebulae nebulas nebulæ
- noun (astronomy) A cloud in outer space consisting of gas or dust (e.g. a cloud formed after a star explodes).
- noun (archaic, medicine) A white spot or slight opacity of the cornea.
- noun (obsolete, medicine) A cloudy appearance in the urine.
Etymology
Learned borrowing from Latin nebula (“little cloud, mist”). First attested in 1655. Akin to Ancient Greek νεφέλη (nephélē, “cloud”), German Nebel (“mist, nebula”), Old Norse nifl, Polish niebo (“sky, heaven”), Russian не́бо (nébo, “sky”).
Webster’s 1913
- noun A faint, cloudlike, self-luminous mass of matter situated beyond the solar system among the stars. True nebulæ are gaseous; but very distant star clusters often appear like them in the telescope.
- noun (a) A white spot or a slight opacity of the cornea.
Etymology [L., mist, cloud; akin to Gr. nebel mist, OHG. nebul, D. nevel, Skr. nabhas cloud, mist. Cf. Nebule.]
Sources: Wiktionary · Webster’s 1913 — from the Wiktionary entry “nebula”, CC BY-SA 4.0. Details