1650s, from Dutch gas, probably from Greek khaos "empty space" (see chaos). The sound of Dutch "g" is roughly equivalent to that of Greek "kh." First used by Flemish chemist J.B. van Helmont (1577-1644), probably influenced by Paracelsus, who used khaos in an occult sense of "proper elements of spirits" or "ultra-rarified water," which was van Helmont's definition of gas.
Modern scientific sense began 1779, with later specialization to "combustible mix of vapors" (1794, originally coal gas); "anesthetic" (1894, originally nitrous oxide); and "poison gas" (1900). Meaning "intestinal vapors" is from 1882. "The success of this artificial word is unique" [Weekley]. 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, it is American English, first recorded 1905.
1886, "to supply with gas," from gas (n.). Sense of "poison with gas" is from 1889 as an accidental thing, from 1915 as a military attack. Related: Gassed; gassing.
n. pl. gas·es or gas·ses
The state of matter distinguished from the solid and liquid states by relatively low density and viscosity, relatively great expansion and contraction with changes in pressure and temperature, the ability to diffuse readily, and the spontaneous tendency to become distributed uniformly throughout any container.
A substance in the gaseous state.
A gaseous fuel, such as natural gas.
A gaseous asphyxiant, an irritant, or a poison.
A gaseous anesthetic, such as nitrous oxide.
To treat chemically with gas.
To overcome, disable, or kill with poisonous fumes.
To give off gas.
One of four main states of matter, composed of molecules in constant random motion. Unlike a solid, a gas has no fixed shape and will take on the shape of the space available. Unlike a liquid, the intermolecular forces are very small; it has no fixed volume and will expand to fill the space available.
gaseous adjective (gās'ē-əs, gāsh'əs)
A strong type of marijuana obtained from a cultivated strain of Indian hemp: He remembers an uncle getting so mean on ganja, he kills his girlfriend
[1800+ Narcotics; fr Hindi; adopted from West Indian use]