n. | 1. | A device, usually of metal, consisting of a frame with one more movable tongues or catches, used for fastening things together, as parts of dress or harness, by means of a strap passing through the frame and pierced by the tongue. |
| 2. | A distortion bulge, bend, or kink, as in a saw blade or a plate of sheet metal. |
| 3. | A curl of hair, esp. a kind of crisp curl formerly worn; also, the state of being curled. |
| 4. | A contorted expression, as of the face. |
v. t. | 1. | To fasten or confine with a buckle or buckles; as, to buckle a harness. |
| 2. | To bend; to cause to kink, or to become distorted. |
| 3. | To prepare for action; to apply with vigor and earnestness; - formerly, generally used reflexively, but by mid 20th century, usually used with down; - as, the programmers buckled down and worked late hours to finish the project in time for the promised delivery date. |
| 4. | To join in marriage. |
v. i. | 1. | To bend permanently; to become distorted; to bow; to curl; to kink. |
| 2. | To bend out of a true vertical plane, as a wall. |
| 3. | To yield; to give way; to cease opposing. |
| 4. | To enter upon some labor or contest; to join in close fight; to struggle; to contend. |