A mixture of gaseous hydrocarbons associated with petroleum deposits; mostly methane with smaller amounts of ethane, propane and butane; principally used as a fuel.

Nitrous oxide, especially when used as an anaesthetic.

(Canada, US) filling station / petrol station; an establishment which sells gasoline (petrol) and diesel

(chemistry) A gas which does not undergo chemical reactions. / (chemistry, specifically) A noble gas.

(chemistry) Any of the elements of group 18 of the periodic table, being monatomic and (with very limited exceptions) inert.

A tear gas formed by mixing o-chlorobenzalmalononitrile powder with a dispersal liquid.

Any lachrymatory, non-lethal chemical compound that causes the eyes to sting and water and/or irritates the respiratory system, mostly used for controlling crowds during riots or as self-defense.

To use tear gas.

chloroacetophenone used as tear gas for riot control, although it is normally replaced nowadays with CS gas.

A gas, such as helium or hydrogen, that is used to produce buoyancy for e.g. balloons or airships.