Dictionary

rarefy en · VERB

Pronunciation

• (Southern-England) audio
• /ˈɹɛəɹəˌfaɪ/

Etymology

From Middle English rarefien, from Old French rarefier (French raréfier), from Latin rarefacere (“make rare”). By surface analysis, rare + -fy.

Meanings

1. (transitive) To make rare, thin, porous, or less dense.
   • By means of this gauge, Mr. Smeaton judged that his machine was incomparably better than any former one, as it seemed to rarefy the air in the receiver 1000, or even 2000 times, while the best of these only rarefied it about 140[…] 1815, A Philosophical and Mathematical Dictionary: Containing an Explanation of the Terms, and an Account ... by Charles Hutton ... vol. 1[-2], page 56:
2. (intransitive) To become rare, thin or less dense.
   • As water rarefies, it evaporates, forming visible steam, and this may be a step toward the final category of reality, fire. Anyone who has held a hand over a boiling kettle may feel the truth of this.[…] 2009, John C. Malone, Psychology: Pythagoras to Present, MIT Press, →ISBN, page 28:
   • Given the high quantity of water molecules in the human body it is worthy of note at this point that moisture rarefies when heated.[…] 2019 November 29, Peta Morton, Ancient Teachings for Modern Times: The Way To a Rich and Deeply Satisfying Life, John Hunt Publishing, →ISBN:
   • For if The^([sic]) water rarefies and then Condenses, all that great mass of water of the Lake of the Ilinois rises in its vast basin when it rarefies, and falls when it condenses. And, as water always rises as much as it falls, it would[…] 1916, Wisconsin Geological and Natural History Survey, Bulletin, page 293:

Forms

Antonyms

condense

Relateds

rarefaction

Synonyms

stretch

Translations (46)

es enrarecer (to enlarge without adding new matter) · bg раздувам (to enlarge without adding new matter) · bn তরল বা পাতলা করা (to make rare etc.) · de verdünnen (to make rare etc.) · fi ohentaa (to enlarge without adding new matter) · be разрэ́джваць (to make rare etc.) · es rarefacerse (to enlarge without adding new matter) · ru разреди́ть (to make rare etc.) · mi whakaonge (to make rare etc.) · es rarear (to enlarge without adding new matter) · fi harventaa (to make rare etc.) · pl rafinować (to enlarge without adding new matter) · de expandieren (to enlarge without adding new matter) · be разрэ́дзіць (to make rare etc.) · pl rozrzedzić (to make rare etc.) · de verfeinern (to make rare etc.) · es rarefacer (to make rare etc.) · uk розріди́ти (to make rare etc.) · fi ohentaa (to make rare etc.) · pl zrafinować (to enlarge without adding new matter) · it rarefare (to make rare etc.) · de selektieren (to make rare etc.) · es enrarecer (to make rare etc.) · uk розрі́джувати (to make rare etc.) · fi harventaa (to enlarge without adding new matter) · bg разреждам (to make rare etc.) · de ausdünnen (to make rare etc.) · pl rozrzedzać (to make rare etc.) · ru разрежа́ть (to make rare etc.) · ro rarefia (to make rare etc.) · sl razredčiti (to make rare etc.) · de expandieren (to make rare etc.) · pl rozcieńczyć (to make rare etc.) · de verlängern (to enlarge without adding new matter) · de evakuieren (to make rare etc.) · sv förtunna (to make rare etc.) · pl rozcieńczać (to make rare etc.) · pt rarefazer (to make rare etc.) · la rārēfaciō (to make rare etc.) · de rarefizieren (to make rare etc.) · es rarificarse (to enlarge without adding new matter) · fr raréfier (to make rare etc.) · de aufblasen (to enlarge without adding new matter) · es rarificar (to make rare etc.) · ca enrarir (to make rare etc.) · es rarear (to make rare etc.)