(idiomatic) To expose to air; to leave open or spread out, as to allow odor or moisture to dissipate. / (by extension) To discuss in the open; to address an issue or conflict that has long been avoided.

(obsolete, inorganic chemistry) carbon dioxide, carbonic acid

(obsolete, chemistry) oxygen

(chemistry, now historical) Hydrogen.

(chemistry, obsolete) Any of various gases considered noxious to humans, including carbon dioxide and nitrogen.

(obsolete, chemistry) hydrogen sulfide

(chemistry, obsolete) nitrogen gas

(chemistry, now historical) Carbon dioxide; carbonic acid.

(now historical) Air thought to be charged with nitre. / (chemistry, now historical) Nitric oxide, NO.

(obsolete, chemistry) oxygen