Standard Lemma guide

rarefaction

noun · 2 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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No pronunciation record was provided for this word.

1

noun

Meaning 1

A reduction in the density of a material, especially that of a fluid.

Definition source: English Wiktionary via Wiktextract

Usage: countable, uncountable

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

2

noun

Meaning 2

a decrease in the density of something

Definition source: Princeton WordNet 3.0

Examples

  • a sound wave causes periodic rarefactions in its medium

Meaning relationships

Synonyms: none provided

Antonyms: none provided

Broader terms: concentration

History

Etymology

From Middle French raréfaction. By surface analysis, rarefy + -faction.

Across languages

Translations

20 source translations are retained for this English entry.

  • Bengali: তনুকরণ (tonukron) — reduction in the density of a material
  • Bengali: তনুভবন (tonubhobon) — reduction in the density of a material
  • Bulgarian: разреждане (razreždane) — reduction in the density of a material
  • Catalan: enrariment — reduction in the density of a material
  • Catalan: rarefacció — reduction in the density of a material
  • Chinese Mandarin: 稀疏 (xīshū) — reduction in the density of a material
  • Chinese Mandarin: 疏鬆 /疏松 (shūsōng) — reduction in the density of a material
  • Finnish: harventaminen — reduction in the density of a material
  • Finnish: ohentaminen — reduction in the density of a material
  • Finnish: harventuminen — reduction in the density of a material
  • Finnish: ohentuminen — reduction in the density of a material
  • Macedonian: проретчување (proretčuvanje) — reduction in the density of a material
  • Polish: rozrzedzenie — reduction in the density of a material
  • Polish: rozcieńczenie — reduction in the density of a material
  • Portuguese: rarefação — reduction in the density of a material
  • Russian: разреже́ние (razrežénije) — reduction in the density of a material
  • Spanish: rarefacción — reduction in the density of a material
  • Spanish: enrarecimiento — reduction in the density of a material
  • Turkish: seyrelme — reduction in the density of a material
  • Turkish: seyrekleşme — reduction in the density of a material