[ nok-tuh-loo-suh nt ]
/ ˌnɒk təˈlu sənt /

adjective Meteorology.

(of high-altitude clouds) visible during the short night of the summer.

Origin of noctilucent

First recorded in 1885–90; nocti- + lucent

OTHER WORDS FROM noctilucent

noc·ti·lu·cence, noun Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

British Dictionary definitions for noctilucent

/ (ˌnɒktɪˈluːsənt) /


shining at night, usu. of very thin high altitude clouds observable in the summer twilight sky

Derived forms of noctilucent

noctilucence, noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for noctilucent

[ nŏk′tə-lōōsənt ]

Luminous at night. The term is used especially to describe certain high atmospheric cloud formations visible during summer nights at high latitudes.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.