noun pl. gases or gasses gas′·ses (gas′iz)

1. the fluid form of a substance in which it can expand indefinitely and completely fill its container; form that is neither liquid nor solid; vapor
2. any mixture of flammable gases used for lighting, heating, or cooking
3. any gas, as nitrous oxide, used as an anesthetic
4. any substance, as phosgene, intentionally dispersed through the atmosphere, as in war, to act as a poison, irritant, or asphyxiant
5. various gaseous substances formed by living or decaying matter, esp. if formed in the stomach, bowels, etc.
6. Informal gasoline
7. ☆ Slang
   1. idle or boastful talk
   2. something or someone that is very pleasing, exciting, amusing, etc. the movie was a gas
8. Mining a mixture of firedamp with air, that explodes if ignited

Etymology: ModL, altered by Van Helmont (1577-1644), Belgian chemist (with g- pronounced, as in Du, as a voiced fricative) < Gr chaos, air (see chaos), term used by Paracelsus

transitive verb gassed, gassing gas′·sing

1. to supply with gas
2. to subject to the action of gas
3. to injure or kill by gas, as in war
4. ☆ Slang to thrill, delight, amuse greatly, etc.

intransitive verb

1. to give off gas
2. ☆ Slang to talk in an idle or boastful way

adjective