jack-knife

English

Wikipedia

Alternative forms

• jackknife (Note: the two spellings appear roughly equally common.)

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. (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.

4. (statistics) Alternative spelling of jackknife.

Translations

a compact folding knife

Dutch: zakmes (nl) n. Finnish: linkkuveitsi (fi) German: Taschenmesser (de) n. Greek: σουγιάς (el) (sougiás) m.

Hungarian: bicska (hu) Spanish: navaja (es) f. West Frisian: bûsmês n., knyft n.

the front-dive pike

a semi-trailer truck accident

statistics — see jackknife

See also

• clasp-knife
• flick knife
• penknife
• pocketknife, pocket knife
• Swiss Army knife
• switchblade

Verb

jack-knife (third-person singular simple present jack-knifes, present participle jack-knifing, simple past and past participle jack-knifed)

1. To fold in the middle, as a jackknife does.

   The cat jackknifed in the air and landed gracefully on its feet.

2. (colloquial) To cause a semi-trailer truck to fold like a jackknife in a traffic accident.

   Before I knew what was happening, I'd jack-knifed the rig like nobody's business.

   Before I knew what was happening, I'd jack-knifed like nobody's business.