(geology) A large underground pool of molten rock lying under the surface of the earth's crust.

(euphemistic, obsolete) Sex; fornication. / The work of a chambermaid.

(government) The lower legislative chamber in a bicameral legislature; in many cases, the one that is directly elected and/or has more practical power, such as the power to raise and spend money.

(government) The upper legislative chamber in a bicameral legislature; usually smaller and having more restricted power than the lower chamber.

A chamber, typically underground, in which young (animals or insects) are born and raised until old enough to venture outside

plural of living chamber

(uncountable) A genre of opera written to be performed with a chamber ensemble. / (countable) An individual opera in this genre.

(government, rare) The single legislative chamber of a unicameral legislature.

plural of sole chamber

A room used by divers to gradually readjust to normal air pressure.