jackknife

¹jack·knife

noun \ˈjak-ˌnīf\

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

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

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

Examples of JACKKNIFE

1. The truck jackknifed on the icy road.

First Known Use of JACKKNIFE

1806