Definition of: vinegar

(vin′ə·gər) noun
1. An acid liquid obtained by the acetous fermentation of alcoholic liquids, as cider, beer, wine, etc., and used as a condiment and preservative.
2. Med. A preparation of dilute acetic acid.
3. Anything metaphorically sour or soured, as a face; acerbity, as of speech. [<OF vyn egre, vinaigre <vin wine (<L vinum) + aigre, egre sour <L acer sharp]
—vin′e·gar·ish adjective