noctilucent cloud

noc·​ti·​lu·​cent cloud | \ˌnäk-tə-ˈlü-sᵊnt- \

Definition of noctilucent cloud 

: a luminous thin usually colored cloud seen especially at twilight at a height of about 50 miles (80 kilometers)

Examples of noctilucent cloud in a Sentence

Recent Examples on the Web

The first time people reported noticing noctilucent clouds was in 1880s after the massive eruption of Krakatau, a volcano in Indonesia. Rachel Becker, The Verge, "How to capture the eerie nighttime clouds of climate change," 6 July 2018 What caught my eye, and the eyes of several other meteorologists, was the idea that these could be noctilucent clouds, instead. Kathryn Prociv, Washington Post, "Extremely rare, colorful nighttime clouds shine over Arizona," 30 Mar. 2018 People living in high latitude areas (between 45º and 70º above or below the Equator) have the best chance of seeing noctilucent clouds. Andrew Fazekas, National Geographic, "Eerie Clouds Glow at Night—How to See Them," 22 June 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'noctilucent cloud.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of noctilucent cloud

circa 1934, in the meaning defined above

History and Etymology for noctilucent cloud

noctilucent "luminous in the dark," from Latin noct-, nox night entry 1 + -i- -i- + lucent

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The first known use of noctilucent cloud was circa 1934

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the figure or shape of a crescent moon

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