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Pronunciation: as′id


  1. A compound yielding a hydrogen ion in a polar solvent (in water); acids form salts by replacing all or part of the ionizable hydrogen with an electropositive element or radical.
  2. Colloquially, 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 not shown here, see specific names.

[L. acidus, sour]

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© Copyright 2018 Wolters Kluwer. All Rights Reserved. Review date: Sep 19, 2016.