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1

jackknife

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noun jack·knife \ˈjak-ˌnīf\

Simple Definition of jackknife

  • : a small knife that has a folding blade

  • : a dive in which you bend from the waist and touch your ankles and then straighten out

Full Definition of jackknife

  1. 1 :  a large strong pocketknife

  2. 2 :  a dive executed headfirst in which the diver bends from the waist and touches the ankles while holding the knees unbent and then straightens out

1711

First Known Use of jackknife

1711


2

jackknife

verb jack·knife

Simple Definition of jackknife

  • : to bend in the middle like a folding jackknife; especially of a large truck : to have the back part slide out of control toward the front part

Full Definition of jackknife

  1. transitive verb
  2. 1 :  to cut with a jackknife

  3. 2 :  to cause to double up like a jackknife

  4. intransitive verb
  5. 1 :  to double up like a jackknife <jackknifed into a seat beside me, folding up his six feet eight — Lady Bird Johnson>

  6. 2 :  to turn and form an angle of 90 degrees or less with each other —used especially of a tractor-trailer combination

Examples of jackknife

  1. The truck jackknifed on the icy road.



1806

First Known Use of jackknife

1806



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