Vinegar

Webster's Dictionary of the English Language

·adj Hence, anything sour;

— used also metaphorically.

II. Vinegar ·vt To convert into vinegar; to make like vinegar; to render sour or sharp.

III. Vinegar ·adj 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.