1. A compound yielding a hydrogen ion in a polar solvent (e.g., in water); acids form salts by replacing all or part of the ionizable hydrogen with an electropositive element or radical.
2. In popular language, any chemical compound that has a sour taste (given by the hydrogen ion).
3. Sour; sharp to the taste.
4. Relating to acid; giving an acid reaction. For individual acids, see specific names.
Origin
[L. acidus, sour]
bile acids
Brønsted acid
conjugate acid
dibasic acid
inorganic acid
Lewis acid
monobasic acid
organic acid
polybasic acid
ruberythric acid
wax acid