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

Supply chain expert and Wichita State University professor Usha Haley said the Jubail complex in Saudi Arabia supplied about 70 percent of the world’s high-purity polyphenylene ether resin. —Kevin Williams, CNBC, 7 June 2026

Regulated access is no longer just about listing a bitcoin or ether contract. —Sean Lee, Forbes.com, 1 June 2026

Noun

Recaps are essential for making sure meeting action items and decisions aren’t lost in the ether. —Shani Harmon, Forbes.com, 28 May 2026

Something changed in the ether after the 2024 presidential election, and Remake became a casualty of shifting priorities and distractions, from global geopolitics to a shaky economy and evolving consumer motivations. —Kate Nishimura, Footwear News, 20 May 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