Word of the Day:

1 : any of numerous clouds of gas or dust in interstellar space

2 : any of the very large groups of stars and associated matter that are found throughout the universe; especially : a galaxy other than the Milky Way — not used technically

The explosion of a supernova leaves behind a nebula from which, upon cooling, new stars and planets may develop.

"A dazzling image of Messier 17, a reddish nebula 5,500 light-years from Earth, provides a detailed view of its newborn stars, gas clouds and dust." — Sindya N. Bhanoo, The New York Times, 28 Sept. 2015

More example sentences

The history of the word nebula is not lost in the mists of time, although its history does get misty at points. The word traces back to the Latin word (spelled the same way as our modern term) for "mist" or "cloud." In its earliest English uses in the 1600s, nebula referred to a cloudy speck or film on the eye that caused vision problems. It 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, but the first uses of nebulous in the astronomical sense don't appear in English until the late 1700s, well after the discovery of interstellar nebulae.