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

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

In market capitalization, ether is second, with XRP in fourth, solana in sixth and cardano in eighth, according to CoinMarketCap.com. —Juliana Kim, NPR, 4 Mar. 2025

Trump said on social media that his January executive order on digital assets would create a stockpile of currencies including bitcoin, ether, XRP, SOL and ADA. —Trevor Hunnicutt, USA TODAY, 2 Mar. 2025

In a post on Truth Social, Trump said that in addition to Bitcoin, the strategic reserve would include ether, XRP, Solana’s SOL token, and Cardano’s ADA coin. —Dylan Butts,anniek Bao, CNBC, 13 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