GNU Dico
From WordNet dictionary, version 3.0:
gas
n. 1. 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
Synonyms: gaseous state
2. a fluid in the gaseous state having neither independent shape nor volume and being able to expand indefinitely
3. a volatile flammable mixture of hydrocarbons (hexane and heptane and octane etc.) derived from petroleum; used mainly as a fuel in internal-combustion engines
Synonyms: gasoline, gasolene, petrol
4. a state of excessive gas in the alimentary canal
Synonyms: flatulence, flatulency
5. a pedal that controls the throttle valve; "he stepped on the gas"
Synonyms: accelerator, accelerator pedal, gas pedal, throttle, gun
6. a fossil fuel in the gaseous state; used for cooking and heating homes
Synonyms: natural gas
v. 1. attack with gas; subject to gas fumes; "The despot gassed the rebellious tribes"
2. show off
Synonyms: boast, tout, swash, shoot a line, brag, blow, bluster, vaunt, gasconade