n. & v.
n. (pl. gases) 1 any airlike substance which moves freely to fill any space available, irrespective of its quantity. 2 a such a substance (esp. found naturally or extracted from coal) used as a domestic or industrial fuel (also attrib. : gas cooker; gas fire). b an explosive mixture of firedamp with air. 3 nitrous oxide or another gas used as an anaesthetic (esp. in dentistry). 4 a gas or vapour used as a poisonous agent to disable an enemy in warfare. 5 US colloq. petrol, gasoline. 6 sl. pointless idle talk; boasting. 7 sl. an enjoyable, attractive, or amusing thing or person.
v. (gases, gassed, gassing) 1 tr. expose to gas, esp. to kill or make unconscious. 2 intr. give off gas. 3 tr. (usu. foll. by up) US colloq. fill (the tank of a motor vehicle) with petrol. 4 intr. colloq. talk idly or boastfully. gas chamber an airtight chamber that can be filled with poisonous gas to kill people or animals. gas chromatography chromatography employing gas as the eluent. gas-cooled (of a nuclear reactor etc.) cooled by a current of gas. gas fire a domestic fire using gas as its fuel. gas-fired using gas as the fuel. gas gangrene a rapidly spreading gangrene of injured tissue infected by a soil bacterium and accompanied by the evolution of gas. gas mask a respirator used as a defence against poison gas. gas meter an apparatus recording the amount of gas consumed. gas oil a type of fuel oil distilled from petroleum and heavier than paraffin oil. gas plant Bot. fraxinella. gas-proof impervious to gas. gas ring a hollow ring perforated with gas jets, used esp. for cooking. gas station US a filling-station. gas-tight proof against the leakage of gas. gas turbine a turbine driven by a flow of gas or by gas from combustion.
[ invented by J. B. van Helmont, Belgian chemist d. 1644, after Gk khaos chaos ]