Definition of jackknife
1 : a large strong pocketknife
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
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First Known Use of jackknife
1711
jackknife
Definition of jackknife
intransitive verb
1 : to double up like a jackknife jackknifed into a seat beside me, folding up his six feet eight — Lady Bird Johnson
2 : to turn and form an angle of 90 degrees or less with each other —used especially of a tractor-trailer combination
transitive verb
1 : to cause to double up like a jackknife
2 : to cut with a jackknife
Examples of jackknife in a Sentence
The truck jackknifed on the icy road.
First Known Use of jackknife
1806
JACKKNIFE Defined for English Language Learners
jackknife
playDefinition of jackknife for English Language Learners
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: a small knife that has a folding blade
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: a dive in which you bend from the waist and touch your ankles and then straighten out
jackknife
Definition of jackknife for English Language Learners
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: 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
Definition of jackknife for Students
jackknives
\-ˌnīvz\: a knife that has a folding blade or blades and can be put in a pocket
Definition of jackknife for Students
jackknifed
;jackknifing
: to double up like a jackknife
Learn More about jackknife
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See words that rhyme with jackknife Spanish Central: Translation of jackknife Nglish: Translation of jackknife for Spanish speakers Britannica English: Translation of jackknife for Arabic speakers
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