[ nuh-byoo-lee-uh m ]
/ nəˈbyu li əm /

noun Astronomy.

a hypothetical element once thought to be present in emission nebulae because of certain unidentified spectral lines, now known to be forbidden transitions of oxygen and nitrogen ions.


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Origin of nebulium

First recorded in 1895–1900; nebul(a) + -ium Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for nebulium

  • The whole thing aglow with the green light of nebulium and blazing with the stars behind it.

    Out Around Rigel|Robert H. Wilson