To Sour

1. (transitive) To make sour.
2. (intransitive) To become sour.
3. (transitive) To spoil or mar; to make disenchanted.
4. (intransitive) To become disenchanted.
5. (transitive) To make (soil) cold and unproductive
6. To macerate (lime) and render it fit for plaster or mortar.
7. (transitive) To process (fabric) after bleaching, using hydrochloric acid or sulphuric acid to wash out the lime.