any base or hydroxide, as soda, potash, etc. that is soluble in water and gives a high concentration of hydroxyl ions in solution; specif., any of the hydroxides and carbonates of the alkali metals
any soluble substance, as a mineral salt or mixture of salts, that can neutralize acids, has a pH greater than 7.0, and turns litmus blue: strong alkalies are caustic
See alkali in American Heritage Dictionary 4
(ălˈkə-līˌ)
nounpl.al·ka·lis or al·ka·lies
A carbonate or hydroxide of an alkali metal, the aqueous solution of which is bitter, slippery, caustic, and characteristically basic in reactions.
Any of various soluble mineral salts found in natural water and arid soils.
Alkali metal.
A substance having highly basic properties; a strong base.