: a medium that in the wave theory of light permeates all space and transmits transverse waves
a: a light volatile flammable liquid C4H10O used especially formerly chiefly as an anesthetic—called also diethyl ether, ethyl ether, ethyl oxideb: any of various organic compounds characterized by an oxygen atom attached to two carbon atoms
Any of a class of organic compounds whose molecular structure has an oxygen atom interposed between two carbon atoms that are part of hydrocarbon molecules. Ethers have the general chemical formula ROR, in which R and R represent the hydrocarbons. They resemble alcohols but generally are less dense, less soluble in water, more volatile, and more inert. They are used in chemical processing, for extraction and separation of chemicals, and as solvents. Some are used as insecticides and soil fumigants. They are also used in medicine and pharmacology. Codeine is the methyl ether of morphine. The term ether often refers to ethyl ether (CHOCH), best known as an anesthetic but also used as a solvent, an extractant, and a reaction medium.