<p><strong>Verb (used without object)</strong></p><ul><li>(of a horn or whistle) to give forth its characteristic sound.</li><li>to make a sound resembling that of a horn, whistle, or the like.</li><li>to sound or blow a horn, whistle, or wind instrument.</li></ul><p><strong>Verb (used with object)</strong></p><ul><li>to cause (a horn, whistle, or wind instrument) to sound.</li><li>to sound (notes, music, etc.) on a horn or the like.</li></ul><p><strong>Noun</strong></p><ul><li>an act or sound of tooting.</li><li>Slang: cocaine.</li></ul>