<p><strong>Noun</strong></p><ul><li>A clasp consisting of a rectangular or curved rim with one or more movable tongues, fixed to one end of a belt or strap, used for fastening to the other end of the same strap or to another strap.</li><li>Any similar contrivance used for such purposes.</li><li>An ornament of metal, beads, etc., of similar appearance.</li><li>A bend, bulge, or kink, as in a board or saw blade.</li></ul><p><strong>Verb</strong></p><ul><li>(Used with object)<ul><li>Buckled, buckling. To fasten with a buckle or buckles: "Buckle your seat belt."</li><li>To shrivel, by applying heat or pressure; bend; curl.</li><li>To prepare (oneself) for action; apply (oneself) vigorously to something.</li><li>To bend, warp, or cause to give way suddenly, as with heat or pressure.</li></ul></li><li>(Used without object)<ul><li>Buckled, buckling. To close or fasten with a buckle: "Grandmother always wore shoes that buckled."</li><li>To prepare oneself or apply oneself: "The student buckled to the lesson."</li><li>To bend, warp, bulge, or collapse: "The bridge buckled in the storm."</li><li>To yield, surrender, or give way to another (often followed by under): "She refused to take the medicine, but buckled under when the doctor told her to."</li></ul></li></ul><p><strong>Verb Phrase</strong></p><ul><li>To fasten one's belt, seat belt, or buckles: "She won't start the car until we've all buckled up."</li><li>To set to work with vigor; concentrate on one's work: "He was by nature a daydreamer and found it hard to buckle down."</li></ul>