gas Look up gas at Dictionary.com
1658, from Du. gas, probably from Gk. khaos "empty space" (see chaos). The sound of Du. "g" is roughly equivalent to that of Gk. "kh." First used by Flem. chemist J.B. van Helmont (1577-1644), probably influenced by Paracelsus, who used khaos in occult sense of "proper elements of spirits" or "ultra-rarified water," which was van Helmont's definition of gas. Modern scientific sense began 1779, focused on "combustible mix of vapors" (1794, originally coal gas); "anesthetic" (1894, originally nitrous oxide); and "poison gas" (1900). Meaning "intestinal vapors" is from 1882. Slang sense of "empty talk" is from 1847; slang meaning "something exciting or excellent" first attested 1953, from earlier hepster slang gasser in the same sense (1944). Gas also meant "fun, a joke" in Anglo-Irish and was used so by Joyce (1914). As short for gasoline (q.v.), it is Amer.Eng., first recorded 1905.