1. A carbonate of ammonium, (NH₄)₂CO₃.
2. The white, crystalline double salt of ammonium bicarbonate and ammonium carbamate, NH₄HCO₃·NH₂COONH₄, produced commercially and used in smelling salts and baking powder.

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.