[jak-nahyf] 
noun, plural -knives, verb, -knifed, -knif⋅ing, adjective | 1. | a large pocketknife. |
| 2. | Fancy Diving. a dive in which the diver bends in midair to touch the toes, keeping the legs straight, and then straightens out. |
| 3. | to bend or double over like a jackknife: The prizefighter jackknifed and fell when he was hit in the stomach. |
| 4. | (of a trailer truck) to have the cab and trailer swivel at the linkage until they form a V shape, as the result of an abrupt stop or accident. |
| 5. | (in diving) to perform a jackknife. |
| 6. | to move rapidly at an abrupt angle. |
| 7. | to cause to jackknife: The blow jackknifed the prizefighter. |
| 8. | to cut with a jackknife. |
| 9. | resembling a jackknife, as in its shape, function, or manner of opening and folding. |
