saleratus n a white soluble compound (NaHCO3) used in effervescent drinks and in baking powders and as an antacid Usage(s) In the finals, Sonya spelled baccalaureate, saleratus and aileron correctly, drew a smile by asking whether the pronouncer meant an "ape or an underground worker" when he asked . Synonym(s) bicarbonate of soda sodium hydrogen carbonate sodium bicarbonate baking soda