jack-knives

Noun

jack-knife (plural jack-knives)

1. A compact folding knife.
   • He kept a jack-knife in his pocket for various tasks.
2. The front-dive pike, in which the body folds and unfolds.
   • It took me hundreds of dives to master even the simple jackknife.
3. An abdominal exercise where knees and torso are raised from a lying position.
4. (colloquial) A semi-trailer truck accident in which the vehicle mimics the closing of a jack-knife.
   • I have seen several jack-knives along that dangerous stretch of road.
5. A game of skill played with a pocket knife in which participants try to throw or flip the knife to stick upright in the ground at specified points or areas.
   • Over at the stable, the men joke and drink whiskey, talk crops and play jack-knife […]1948, Truman Capote, chapter 1, in Other Voices, Other Rooms, Part One

   Synonyms:

   mumblety peg

See all 7 meanings of jack-knife