Phrase guide

noctilucent cloud

noun · 1 senses · updated from the 2026-07-25 local source snapshot

Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.

Sound

Pronunciation

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1

noun

Meaning 1

Clouds characterized by their electric-blue or silvery-white, wispy streaks, filaments, or ripples high in the twilight sky; Earth's highest clouds, glowing at the edge of space, serving as indicators of climate change, showing increased frequency and visibility linked to human activities like methane emissions and rocket launches; maintain unique formation in frigid summer mesosphere, from ice crystals on meteoric dust, providing scientists with high-altitude atmospheric window into changes in upper atmospheric water vapor and dynamics.

Definition source: English Wiktionary via Wiktextract

Topics: climatology, meteorology, natural-sciences

Examples

  • See also: noctilucent, NLC

Meaning relationships

Synonyms: night-shining cloud

Antonyms: none provided

History

Etymology

The clouds were studied extensively by German astronomer Otto Jesse, who was the first to photograph them in 1887, and seems to have been the one to coin the term noctilucent cloud.