<p><strong>Verb (used with object)</strong></p><ul><li>to bite or chew on, especially persistently.</li><li>to wear away or remove by persistent biting or nibbling.</li><li>to form or make by so doing: to gnaw a hole through the wall.</li><li>to waste or wear away; corrode; erode.</li><li>to trouble or torment by constant annoyance, worry, etc.; vex; plague.</li></ul><p><strong>Verb (used without object)</strong></p><ul><li>to bite or chew persistently: The spaniel gnawed happily on a bone.</li><li>to cause corrosion: The acid gnaws at the metal.</li><li>to cause an effect resembling corrosion: Her mistake gnawed at her conscience.</li></ul>