ether

[ ee-ther ]

noun

1. Also called diethyl ether,. Chemistry, Pharmacology. a colorless, highly volatile, flammable liquid, C 4 H 10 O, having an aromatic odor and sweet, burning taste, derived from ethyl alcohol by the action of sulfuric acid: used as a solvent and, formerly, as an inhalant anesthetic.
2. Chemistry. (formerly) one of a class of compounds in which two organic groups are attached directly to an oxygen atom, having the general formula ROR.
3. the upper regions of space; the clear sky; the heavens.
4. the medium supposed by the ancients to fill the upper regions of space.
5. Physics. a hypothetical substance supposed to occupy all space, postulated to account for the propagation of electromagnetic radiation through space.

ether

/ ˈiːθə; iːˈθɛrɪk /

noun

1. Also calleddiethyl etherethyl etherethoxyethane a colourless volatile highly flammable liquid with a characteristic sweetish odour, made by the reaction of sulphuric acid with ethanol: used as a solvent and anaesthetic. Formula: C 2 H 5 OC 2 H 5
2. any of a class of organic compounds with the general formula ROR′ where R and R′ are alkyl groups, as in diethyl ether C 2 H 5 OC 2 H 5
3. the ether
   the hypothetical medium formerly believed to fill all space and to support the propagation of electromagnetic waves
4. Greek myth the upper regions of the atmosphere; clear sky or heaven
5. a rare word for air

ether

/ ē′thər /

1. An organic compound in which two hydrocarbon groups are linked by an oxygen atom, having the general structure ROR|||PRIMARY_STRESS|||, where R and R|||PRIMARY_STRESS||| are the two hydrocarbon groups. At room temperature, ethers are pleasant-smelling liquids resembling alcohols but less dense and less soluble in water. Ethers are part of many naturally occurring organic compounds, such as starches and sugars, and are widely used in industry and in making pharmaceuticals.
2. A colorless, flammable liquid used as a solvent and formerly used as an anesthetic. Ether consists of two ethyl groups joined by an oxygen atom. Also called diethyl ether, ethyl ether. Chemical formula: C 4 H 10 O.
3. A hypothetical medium formerly believed to permeate all space, and through which light and other electromagnetic radiation were thought to move. The existence of ether was disproved by the American physicists Albert Michelson and Edward Morley in 1887.

Derived Forms

• etheric, adjective

Other Words From

• e·ther·ic [ih-, ther, -ik, ih-, theer, -], adjective
• su·per·e·ther noun

Word History and Origins

Origin of ether¹

First recorded in 1350–1400; Middle English, from Latin aethēr “the upper air, pure air, ether,” from Greek aithḗr, akin to aíthein “to glow, burn,” Old English ād “funeral pyre,” Latin aestus “heat”

Word History and Origins

Origin of ether¹

C17: from Latin aether, from Greek aithēr, from aithein to burn

Example Sentences

Far from all Londoners falling back on dull neutrals, Durran found red was “in the fashion ether at the time”; makeup designer Naomi Donne also goes crimson for Rita’s lipstick.

From Los Angeles Times

Suffice it to say, everything eventually dissolves into the ether: Close goes away, as do all of Kaplan’s other projects.

From Los Angeles Times

She recalled that during the procedure, she was given "a few puffs of ether" which numbed parts of her body but she was not under anesthesia.

From Salon

We keep making this mistake around Project 2025 where we talk about it as though if Donald Trump is defeated, it will just disappear into the ether.

From Slate

Spot Ethereum ETFs will directly hold Ether, the second-largest cryptocurrency after Bitcoin, allowing investors to own a share of the cryptocurrency through grantor trusts.

From Salon