rarefy

[rair-uh-fahy]

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verb (used with object), rar·e·fied, rar·e·fy·ing.

to make rare or rarer; make less dense: to rarefy a gas.

to make more refined, spiritual, or exalted.

verb (used without object), rar·e·fied, rar·e·fy·ing.

to become rare or less dense; become thinned: Moisture rarefies when heated.

Origin of rarefy

1350–1400; Middle English rarefien < Middle French rarefier < Latin rārēfacere, equivalent to rārē-, combining form of rārus rare¹ (for expected rāri-; orig. of -ē- unclear) + facere to make; see -fy

Related formsrar·e·fi·a·ble, adjectiverar·e·fi·er, noun

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for rarefy

attenuate, trim, shave, lace, reduce, decrease, disperse, weaken, cut, doctor, irrigate, spike, needle, water, cook, diminish, expand, prune, edit, extenuate

Examples from the Web for rarefy

Historical Examples of rarefy

But if warm dry winds blow upon the clouds, they rarefy the vapour to a greater degree, and temporarily disperse the clouds.
The Reason Why
Anonymous
The rarefy of the atmosphere continued to affect the wood-work of the wagons, and the wheels were incessantly falling to pieces.
The Adventures of Captain Bonneville
Washington Irving
But extend this vapour, rarefy it; from so narrow a room as our natural bodies, to any politic body, to a state.
Devotions Upon Emergent Occasions
John Donne
The air consequently was damp and gross, for want of stronger rays to open and rarefy it.
The Boys' and Girls' Plutarch
Plutarch
But as such means are not at disposal, it becomes necessary to place the terminal in the bulb and rarefy the air in the same.
The inventions, researches and writings of Nikola Tesla
Thomas Commerford Martin

British Dictionary definitions for rarefy

rarefy

verb -fies, -fying or -fied

to make or become rarer or less dense; thin out

Derived Formsrarefiable, adjectiverarefier, noun

Word Origin for rarefy

C14: from Old French raréfier, from Latin rārēfacere, from rārus rare 1 + facere to make

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

Word Origin and History for rarefy

late 14c., from Old French rarefier (14c.) and directly from Medieval Latin rarificare, from Latin rarefacere "make rare," from rarus "rare, thin" (see rare (adj.1)) + facere "to make" (see factitious). Related: Rarefied.