n. [ Pref. bi- + carbonate. ] (Chem.) A carbonate in which but half the hydrogen of the acid is replaced by a positive element or radical, thus making the proportion of the acid to the positive or basic portion twice what it is in the normal carbonates; an acid carbonate; -- sometimes called supercarbonate. [ 1913 Webster ]

a white crystalline substance, HNaCO3, with a slight alkaline taste resembling that of sodium carbonate. It is found in many mineral springs and also produced artificially, . It is used in cookery, in baking powders, and as a source of carbonic acid gas (carbon dioxide) for soda water. Called also baking soda, cooking soda, bicarbonate of soda, bicarb, saleratus, and technically, acid sodium carbonate, sodium acid carbonate, primary sodium carbonate, sodium dicarbonate, etc. [ 1913 Webster ]