- Chemistry.
- any of various bases, the hydroxides of the alkali metals and of ammonium, that neutralize acids to form salts and turn red litmus paper blue.
- any of various other more or less active bases, as calcium hydroxide.
- (not in technical use) an alkali metal.
- any of various other compounds, as the carbonates of sodium and potassium.
- a soluble mineral salt or a mixture of soluble salts, present in some soils, especially in arid regions, and detrimental to the growing of most crops.
- a soluble base or a solution of a base
- a soluble mineral salt that occurs in arid soils and some natural waters
