(Science: chemistry) sodium oxide or hydroxide.
Popularly, sodium carbonate or bicarbonate. Caustic soda, sodium hydroxide. Cooking soda, sodium bicarbonate. Sal soda. See sodium carbonate, under Sodium.
(Science: chemical) Soda alum, a mineral consisting of the hydrous sulphate of alumina and soda. Soda ash, crude sodium carbonate; so called because formerly obtained from the ashes of sea plants and certain other plants, as saltwort (salsola). See Sodium. Soda fountain, an apparatus for drawing soda water, fitted with delivery tube, faucets, etc. Soda lye, a lye consisting essentially of a solution of sodium hydroxide, used in soap making. Soda niter. See nitratine. Soda salts, salts having sodium for the base; specifically, sodium sulphate or glauber’s salts. Soda waste, the waste material, consisting chiefly of calcium hydroxide and sulphide, which accumulates as a useless residue or side product in the ordinary Leblanc process of soda manufacture; called also alkali waste. Soda water, originally, a beverage consisting of a weak solution of sodium bicarbonate, with some acid to cause effervescence; now, in common usage, a beverage consisting of water highly charged with carbon dioxide (carbonic acid). Fruit sirups, cream, etc, are usually added to give flavor. See carbonic acid, under Carbonic. Washing soda, sodium carbonate.
Origin: It, soda, in OIt, ashes used in making glass, fr. L. Solida, fem. Of solidus solid; solida having probably been a name of glasswort. See Solid.