1
a
: the rarefied element formerly believed to fill the upper regions of space
b
: the upper regions of space : heavens
2
a
: a light volatile flammable liquid C4H10O used chiefly as a solvent and especially formerly as an anesthetic
b
: any of a class of organic compounds characterized by an oxygen atom attached to two carbon atoms
3
a
or less commonly aether : a medium that in the wave theory of light permeates all space and transmits transverse waves
b
etheric
i-ˈther-ik How to pronounce ether (audio)
-ˈthir-
adjective

Examples of ether in a Sentence

The balloon disappeared into the ether.
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
By allowing OnePay users to hold bitcoin and ether in their mobile app, customers could presumably convert their crypto into cash and then use those funds to make store purchases or pay off card balances. Hugh Son, CNBC, 3 Oct. 2025 Physicists invented ether as a medium through which light waves traveled. Dipangkar Dutta, The Conversation, 3 Oct. 2025 Everything is ether, including the ground beneath your feet. Andy Andersen, Vulture, 18 Sep. 2025 The core, however, remains trading and custody, with bitcoin and ether comprising 88% of platform assets. Marie Poteriaieva, Forbes.com, 9 Sep. 2025 See All Example Sentences for ether

Word History

Etymology

Middle English, from Latin aether, from Greek aithēr, from aithein to ignite, blaze; akin to Old English ād pyre — more at edify

First Known Use

14th century, in the meaning defined at sense 1a

Time Traveler
The first known use of ether was in the 14th century

Browse Nearby Words

Cite this Entry

“Ether.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ether. Accessed 10 Oct. 2025.

Kids Definition

ether

noun
1
a
: an invisible substance once believed to fill the upper regions of space
b
: the upper regions of space : heavens
2
: an easily evaporated flammable liquid used chiefly to dissolve other substances and especially formerly as an anesthetic

Medical Definition

ether

noun
1
: a medium that in the wave theory of light permeates all space and transmits transverse waves
2
a
: a light volatile flammable liquid C4H10O used especially formerly chiefly as an anesthetic

called also diethyl ether, ethyl ether, ethyl oxide

b
: any of various organic compounds characterized by an oxygen atom attached to two carbon atoms

More from Merriam-Webster on ether

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