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

Editor Indya Brown ethers into sporty territory at times too. —Robyn Mowatt, Essence, 14 May 2025

For those unfamiliar, digital twins in the healthcare context are essentially intricate facsimiles of people in the digital ether, constructed from medical records, biometric signals, genomic data and behavioral patterns. —Mika Newton, Forbes.com, 13 May 2025

In the legal ether for months, the plea deal was made public in an almost casual manner by an assistant U.S. attorney at an April 25 hearing. —Dominic Patten, Deadline, 1 May 2025

Over the past year or two, the title has been in my ether. —Kyle Denis, Billboard, 25 Apr. 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