# jack-knife

> English word · Noun

## Definitions
1. A compact folding knife.
2. The front-dive pike, in which the body folds and unfolds.
3. A semi-trailer truck accident in which the vehicle mimics the closing of a jack-knife.
4. 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; mumblety-peg.
5. Alternative spelling of jackknife.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/jack-knife