noun

1. Matter in a state intermediate between liquid and plasma that can be contained only if it is fully surrounded by a solid (or in a bubble of liquid) (or held together by gravitational pull); it can condense into a liquid, or can (rarely) become a solid directly.

   “A lot of gas had escaped from the cylinder.”

2. A chemical element or compound in such a state.

   “The atmosphere is made up of a number of different gases.”

3. 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.

   “Gas-fired power stations have largely replaced coal-burning ones.”

Synonyms: fart, wind, vapor / vapour

verb

1. To kill with poisonous gas.

2. To talk in a boastful or vapid way; chatter.

3. To impose upon by talking boastfully.