The Collaborative International Dictionary of English v.0.48:

Soda \So"da\, n. [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.]
   1. (Chem.)
      (a) Sodium oxide or hydroxide.
      (b) Popularly, sodium carbonate or bicarbonate. Sodium
          bicarbonate is also called baking soda
          [1913 Webster]

   2. same as sodium, used in terms such as bicarbonate of
      soda.
      [PJC]

   3. same as soda water.
      [PJC]

   4. a non-alcoholic beverage, sweetened by various means,
      containing flavoring and supersaturated with carbon
      dioxide, so as to be effervescent when the container is
      opened; -- in different localities it is variously called
      also soda pop, pop, mineral water, and minerals.
      It has many variants. The sweetening agent may be natural,
      such as cane sugar or corn syrup, or artificial, such as
      saccharin or aspartame. The flavoring varies widely,
      popular variants being fruit or cola flavoring.
      [PJC]

   Caustic soda, sodium hydroxide.

   Cooking soda, sodium bicarbonate. [Colloq.]

   Sal soda. See Sodium carbonate, under Sodium.

   Soda alum (Min.), 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 under 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.

   Washing soda, sodium carbonate. [Colloq.]
      [1913 Webster]

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):

baking soda
    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]