The Collaborative International Dictionary of English v.0.48:

Sodium bicarbonate \Sodium bicarbonate\,
   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]

WordNet (r) 3.0 (2006):

sodium bicarbonate
    n 1: a white soluble compound (NaHCO3) used in effervescent
         drinks and in baking powders and as an antacid [syn:
         bicarbonate of soda, sodium hydrogen carbonate, sodium
         bicarbonate, baking soda, saleratus]