<p><strong>Verb</strong></p><ul><li>(used without object) to bark sharply, shrilly, or snappishly; yelp.</li><li>(Slang) to talk shrilly, noisily, or foolishly.</li></ul><p><strong>Noun</strong></p><ul><li>a sharp, shrill, or snappish bark; yelp.</li><li>(Slang) shrill, noisy, or foolish talk.</li><li>the mouth: Keep your yap shut.</li><li>(Slang) an uncouth or stupid person; bumpkin; fool.</li></ul>