Dictionary
1jackknife
noun jack·knife \ˈjak-ˌnīf\
: 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
: 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
Rhymes with JACKKNIFE
alewife, case knife, clasp knife, drawknife, farmwife, fishwife, flick-knife, folklife, good life, goodwife, half-life, highlife, housewife, loosestrife, lowlife, midlife, midwife, nightlife, oldwife, penknife, pro-life, real-life, shelf life, steak knife, still life, true-life, wakerife, whole-life, wildlife
2jackknife
verb
: 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
transitive verb
1
: to cut with a jackknife
2
: to cause to double up like a 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
See jackknife defined for English-language learners
First Known Use of JACKKNIFE
1806
JACKKNIFE Defined for Kids
1jackknife
noun jack·knife \ˈjak-ˌnīf\
plural jack·knives \-ˌnīvz\
Definition of JACKKNIFE for Kids
: a knife that has a folding blade or blades and can be put in a pocket
2jackknife
verb
jack·knifedjack·knif·ing
Definition of JACKKNIFE for Kids
: to double up like a jackknife
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