[nok-tuh-loo-suh nt]

adjective Meteorology.

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

Nearby words

  1. noct. maneq.,
  2. noctambulism,
  3. noctambulous,
  4. nocti-,
  5. noctiluca,
  6. noctis,
  7. noctograph,
  8. noctuid,
  9. noctule,
  10. nocturia

Origin of noctilucent

First recorded in 1885–90; nocti- + lucent

Related formsnoc·ti·lu·cence, noun Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for noctilucent



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

Science definitions for noctilucent



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.