<p><strong>Noun</strong></p><ul><li>the hole, slit, or loop through which a button is passed and by which it is secured.</li><li>a boutonniere.</li><li>a short, straight incision through the wall of a cavity or a canal.</li></ul><p><strong>Verb</strong></p><ul><li>to sew with a buttonhole stitch.</li><li>to make buttonholes in.</li><li>to hold by the buttonhole or otherwise abruptly detain (someone) in conversation: The reporter tried to buttonhole the mayor for a statement on the bus strike.</li></ul>