ether
UK: ˈiːθə | US: ˈiːθər
n. 1. (Chemistry) A volatile, highly flammable liquid formerly used as an anesthetic.
n. 2. (Literary/Archaic) The clear sky or upper regions of air beyond the clouds.
n. 3. (Physics) A hypothetical medium once thought to permeate space and transmit light waves.
Derived from Greek aithēr (αἰθήρ), meaning "upper air" or "pure, fresh air," contrasting with aēr (lower air). In ancient cosmology, ether referred to the celestial substance breathed by gods. Later, alchemists and scientists adopted the term for volatile liquids and hypothetical light-transmitting media. The word’s evolution reflects a shift from mythological to scientific abstraction.
The surgeon used ether to anesthetize the patient before the operation.
Poets often describe celestial beings dwelling in the ether.
19th-century physicists debated whether ether was the medium for light propagation.
The rocket ascended through the clouds into the ether.
Alchemists sought to isolate the "quintessence" or ether from matter.