(1):
(v. t.) To convert into vinegar; to make like vinegar; to render sour or sharp.
(2):
(a.) Hence, anything sour; - used also metaphorically.
(3):
(a.) A sour liquid used as a condiment, or as a preservative, and obtained by the spontaneous (acetous) fermentation, or by the artificial oxidation, of wine, cider, beer, or the like.