ether

1 of 2

noun (1)

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

The concept naturally arose of the ether as a frictionless, incompressible, homogeneous, invisible substance that pervaded all space like a transparent jelly.

—Martin Gardner

b

: airwaves

broadcasting radio signals into the ether

etheric

i-ˈther-ik 

-ˈthir-

adjective

the ether

2 of 2

noun (2)

: the sky

The balloon disappeared into the ether.

plucked an answer out of the ether

—used especially when describing electronic signals that travel through the air

broadcasting radio signals into the ether

sent a message over/through the ether

Examples of ether in a Sentence

Noun (1)

The balloon disappeared into the ether.

Recent Examples on the Web

Noun

Affected assets included ether, XRP, USDT, USDC, Avalanche and BNB across the Ethereum, XRP Ledger, Avalanche, BNB Smart Chain and Arbitrum networks. — Matthew Tan, CNBC, 25 Sep. 2026

Its relevance does not depend on predicting the price of ether or treating blockchain as a replacement for conventional finance. — Karen Koehler, Idaho Statesman, 23 Sep. 2026

Noun

Having been in the ether for some time, the TV version has had a long, winding journey to screen. — Max Goldbart, Deadline, 24 Sep. 2026

Correspondence carried out through EarthLink and Hotmail addresses has, with a few exceptions, vanished into the ether. — Literary Hub, 27 Aug. 2026

Word History

Etymology

Noun (1)

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

Noun (1)

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

Phrases Containing ether

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