(n.) One of a class of caustic bases (which neutralize acids) such as soda, potash, ammonia, and lime\, whose distinguishing peculiarities are solubility in alcohol and water, uniting with oils and fats to form soap, neutralizing and forming salts with acids, turning to brown several vegetable yellows, and changing reddened litmus to blue.

acid acidity agent alkalinity alloisomer anion antacid atom base biochemical cation chemical chemical element chromoisomer compound copolymer dimer element heavy chemicals high polymer homopolymer hydracid inorganic chemical ion isomer macromolecule metamer molecule monomer neutralizer nonacid organic chemical oxyacid polymer pseudoisomer radical reagent sulfacid trimer