Definition of: gas

(gas) noun
1. Physics That fluid form of matter which is compressible within limits, and which, owing to the relatively free movement of its molecules, diffuses readily and is capable of indefinite expansion in all directions.
2. Any gaseous or vaporous mixture other than air: illuminating gas, fuel gas, etc.
3. A single jet of flame supplied by illuminating gas.
4. Laughing gas.
5. Mining An explosive mixture of atmospheric air with firedamp.
6. Slang Empty boasting; chatter.
7. U.S. Colloq. Gasoline.
8. Chlorine or some other highly poisonous or asphyxiating substance used in warfare: also poison gas.
9. Flatulence. See synonyms under FLUID.
—v. gassed, gas·sing v.t.
1. To overcome, affect, or kill by gas or gas fumes.
2. To treat or saturate with gas.
3. To supply with gas or gasoline.
4. To singe so as to free of loose fibers: to gas lace.
5. U.S. Slang To talk boastfully or nonsensically to.
—v.i.
6. To give off gas.
7. U.S. Slang To talk in an idle or empty manner; boast. [Coined by J. B. van Helmont, 1577–1644, Belgian chemist]