<p><strong>Noun</strong></p><ul><li>a sour liquid consisting of dilute and impure acetic acid, obtained by acetous fermentation from wine, cider, beer, ale, or the like: used as a condiment, preservative, etc.</li><li>a solution of a medicinal substance in dilute acetic acid, or vinegar.</li><li>sour or irritable speech, manner, or countenance: a note of vinegar in his voice.</li><li>Informal: vigor; high spirits; vim.</li></ul>