ether

noun

ˈē-thər 

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

ˈē-thər 

: a medium that in the wave theory of light permeates all space and transmits transverse waves

b

: airwaves

etheric

i-ˈther-ik 

-ˈthir-

adjective

Examples of ether in a Sentence

The balloon disappeared into the ether.

Recent Examples on the Web

Other major digital currencies, such as ether, XRP, and solana, experienced even larger declines during the same period. —Amanda Castro, MSNBC Newsweek, 7 Apr. 2025

For institutional investors seeking to allocate a percentage of funds under management to cryptoassets the volatility that continues to exist with existing in traditional cryptoassets such as bitcoin and ether does pose a potential issue. —Sean Stein Smith, Forbes.com, 4 Apr. 2025

Warren sent a letter to Sacks ahead of last week’s first-ever White House Crypto Summit, raising conflict-of-interest concerns and calling on Sacks to disclose any financial holdings in bitcoin, ether, solana, and other assets included in Trump’s initial proposal for a strategic reserve. —Mackenzie Sigalos, CNBC, 14 Mar. 2025

Alongside bitcoin, Trump said that XRP, solana, cardano, and ether will be considered for inclusion. —Joel Khalili, WIRED, 4 Mar. 2025

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

Phrases Containing ether

• diethyl ether
• ether extract
• ethyl ether
• into the ether
• over/through the ether
• the ether

Kids Definition

ether

noun

ˈē-thər 

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

ˈē-thər 

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