<p><strong>Verb</strong></p><ul><li>(used with object) to stop up the mouth of (a person) by putting something in it, thus preventing speech, shouts, etc.</li><li>to restrain by force or authority from freedom of speech; silence.</li><li>to fasten open the jaws of, as in surgical operations.</li><li>to cause to retch or choke.</li><li>Metalworking: to straighten or bend (a bar, rail, etc.) with a gag.</li></ul><p><strong>Noun</strong></p><ul><li>something put into a person's mouth to prevent speech, shouting, etc.</li><li>any forced or arbitrary suppression of freedom of speech.</li><li>a surgical instrument for holding the jaws open.</li><li>a shaped block of steel used with a press to straighten or bend a bar, rail, etc.</li></ul>