gas

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. 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.
2. n. A substance in the gaseous state.
3. n. A gaseous fuel, such as natural gas.
4. n. Gasoline.
5. n. The speed control of a gasoline engine. Used with the: Step on the gas.
6. n. A gaseous asphyxiant, irritant, or poison.
7. n. A gaseous anesthetic, such as nitrous oxide.
8. n. Flatulence.
9. n. Flatus.
10. n. Slang Idle or boastful talk.
11. n. Slang Someone or something exceptionally exciting or entertaining: The party was a gas.
12. v. To treat chemically with gas.
13. v. To overcome, disable, or kill with poisonous fumes.
14. v. To give off gas.
15. v. Slang To talk excessively.
16. gas up To supply a vehicle with gas or gasoline: gas up a car; gassed up before the trip.

Century Dictionary and Cyclopedia

1. n. A substance possessing perfect molecular mobility and the property of indefinite expansion. The term was originally synonymous with air, but was afterward applied to substances supposed (but wrongly—see below) to be incapable of reduction to a liquid or solid state. In accordance with this use a gas was defined to be a permanently elastic fluid or air differing from common air. According to the kinetic theory of gases, now accepted, the molecules of a gas are in a state of rapid motion in right lines, constantly colliding with one another and with the walls of any containing vessel, and hence exerting pressure against them. For example, in the case of air at ordinary temperatures it is calculated that the average velocity of the molecules is about that of a rifle-bullet as it leaves the gun. If a gas is compressed into less volume, the number of impacts against the sides of the containing vessel is increased, and hence the pressure or tension increases, and conversely (Boyle's law). The temperature, according to this theory, is the average kinetic energy of a molecule; hence, increased temperature brings increased momentum, and so increased pressure on the walls of the vessel. This theory also explains many of the phenomena of viscosity, diffusion, etc. By increased pressure and diminished temperature (at least below the critical point) any gas can be reduced to the liquid form, the amount of pressure and degree of cold required differing widely with different gases. The so-called fixed or permanent gases, which were long supposed to be incoercible, as hydrogen, oxygen, nitrogen, etc., yield only to extreme conditions of cold and pressure. There is no essential difference between a gas and a vapor (see vapor), but for convenience the latter name is given to the gaseous form of substances which under the ordinary conditions of temperature and pressure are liquids or solids. Vapors and the gases most easily liquefied deviate most widely from Boyle's law, that the volume is inversely proportional to the pressure, and also from the law of the constant increment of expansion with increase of temperature. Gases are distinguished from liquids by the name of elastic fluids, because of their power of indefinite expansion. (See liquid.) The number of gaseous bodies is great, and they differ greatly in their chemical properties. They are all, however, susceptible of combining chemically with fluid and solid substances. Some of them are of great importance in the arts and manufactures, as, for example, carbonic acid or carbon dioxid, sulphurous acid or sulphur dioxid, and coal-gas. Gases are ordinarily invisible.
2. n. Specifically In coal-mining, any explosive mixture of fire-damp with common air.
3. n. In popular language, a compound of various gases, used for illuminating and heating purposes. It is some form of carbureted hydrogen artificially made and distributed by pipes to points of consumption. The common kind is coal-gas, obtained from bituminous coals by carbonization in retorts at a high temperature. A carbureted hydrogen gas, called water-gas, resulting from the passing of steam through a mass of incandescent carbon and the subsequent admixture of hydrocarbons or other enriching substances, is also used. Oil-gas is an illuminating gas obtained by the distilling at high temperature of petroleum or other liquid hydrocarbons.
4. n. A gas-light: as, the gas is dim; turn down the gas.
5. n. Empty or idle talk; frothy speech; rant.
6. To remove loose filaments from (net, lace, etc.) by passing the material between rollers and exposing it to the action of a large number of minute jets of gas.
7. To talk nonsense or falsehood to; impose upon by wheedling, frothy, or empty speech.
8. To indulge in “gas” or empty talk; talk nonsense.
9. n. Specifically, nitrous-oxid gas when used to produce anæsthesia, most commonly by dentists.
10. To treat with a gas or expose to the action of a gas, as is done with slaked lime in the manufacture of bleaching-powder.
11. To overcome or poison by means of the inhalation of gas.

Wiktionary

1. adj. Ireland, colloquial comical, zany.
2. n. uncountable, chemistry Matter in a state intermediate between liquid and plasma that can be contained only if it is fully surrounded by a solid (or held together by gravitational pull); it can condense into a liquid, or can (rarely) become a solid directly.
3. n. countable, chemistry A chemical element or compound in such a state.
4. n. uncountable A flammable gaseous hydrocarbon or hydrocarbon mixture (typically predominantly methane) used as a fuel, e.g. for cooking, heating, electricity generation or as a fuel in internal combustion engines in vehicles.
5. n. countable A hob on a gas cooker.
6. n. US Methane or other waste gases trapped in one's belly as a result of the digestive process.
7. n. slang A humorous or entertaining event or person.
8. n. baseball A fastball.
9. v. To kill with poisonous gas.
10. v. To talk, chat.
11. v. To emit gas.
12. n. uncountable, US Gasoline; a derivative of petroleum used as fuel.
13. v. US To give a vehicle more fuel in order to accelerate it.
14. v. US To fill (a vehicle's fuel tank) with fuel

GNU Webster's 1913

1. n. An aëriform fluid; -- a term used at first by chemists as synonymous with air, but since restricted to fluids supposed to be permanently elastic, as oxygen, hydrogen, etc., in distinction from vapors, as steam, which become liquid on a reduction of temperature. In present usage, since all of the supposed permanent gases have been liquified by cold and pressure, the term has resumed nearly its original signification, and is applied to any substance in the elastic or aëriform state.
2. n. A complex mixture of gases, of which the most important constituents are marsh gas, olefiant gas, and hydrogen, artificially produced by the destructive distillation of gas coal, or sometimes of peat, wood, oil, resin, etc. It gives a brilliant light when burned, and is the common gas used for illuminating purposes.
3. n. Laughing gas.
4. n. Any irrespirable aëriform fluid.
5. n. same as gasoline; -- a shortened form. Also, the accelerator pedal of a motor vehicle; used in the term “ step on the gas”.
6. n. the accelerator pedal of a motor vehicle; used in the term “ step on the gas”.
7. n. Same as natural gas.
8. n. slang an exceptionally enjoyable event; a good time.
9. v. (Textiles) To singe, as in a gas flame, so as to remove loose fibers.
10. v. To impregnate with gas.
11. v. to expose to a poisonous or noxious gas.

WordNet 3.0

1. n. a fluid in the gaseous state having neither independent shape nor volume and being able to expand indefinitely
2. v. show off
3. v. attack with gas; subject to gas fumes
4. n. a state of excessive gas in the alimentary canal
5. n. a fossil fuel in the gaseous state; used for cooking and heating homes
6. n. a pedal that controls the throttle valve
7. n. a volatile flammable mixture of hydrocarbons (hexane and heptane and octane etc.) derived from petroleum; used mainly as a fuel in internal-combustion engines
8. n. 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