1

jackknife

play
noun jack·knife \ˈjak-ˌnīf\

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

Definition of jackknife

  1. intransitive verb
  2. 1 :  to double up like a jackknife jackknifed into a seat beside me, folding up his six feet eight — Lady Bird Johnson

  3. 2 :  to turn and form an angle of 90 degrees or less with each other —used especially of a tractor-trailer combination

  4. transitive verb
  5. 1 :  to cause to double up like a jackknife

  6. 2 :  to cut with a jackknife

Examples of jackknife in a Sentence

  1. The truck jackknifed on the icy road.

1806

First Known Use of jackknife

1806


JACKKNIFE Defined for English Language Learners

jackknife

play
noun

Definition of jackknife for English Language Learners

  • : 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

jackknife

verb

Definition of jackknife for English Language Learners

  • : 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


JACKKNIFE Defined for Kids

1

jackknife

play
noun jack·knife \ˈjak-ˌnīf\

Definition of jackknife for Students

plural

jackknives

\-ˌnīvz\
  1. :  a knife that has a folding blade or blades and can be put in a pocket


2

jackknife

play
verb jack·knife

Definition of jackknife for Students

jackknifed

;

jackknifing

  1. :  to double up like a jackknife



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