<p><strong>Verb</strong></p><ul><li>(used without object) to feel or express worry, annoyance, discontent, or the like: Fretting about the lost ring isn't going to help.</li><li>(used with object) to torment; irritate, annoy, or vex: You mustn't fret yourself about that.</li><li>to cause corrosion; gnaw into something: acids that fret at the strongest metals.</li><li>to make a way by gnawing, corrosion, wearing away, etc.: The river frets at its banks until a new channel is formed.</li><li>to become eaten, worn, or corroded (often followed by away): Limestone slowly frets away under pounding by the wind and rain.</li><li>to move in agitation or commotion, as water: water fretting over the stones of a brook.</li></ul><p><strong>Noun</strong></p><ul><li>an irritated state of mind; annoyance; vexation.</li><li>a wearing away; erosion; corrosion.</li><li>a worn or eroded place.</li></ul>