jackknife

[ jak-nahyf ]

/ ˈdʒækˌnaɪf /

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See synonyms for jackknife on Thesaurus.com

noun, plural jack·knives.

a large pocketknife.

Fancy Diving. a dive in which the diver bends in midair to touch the toes, keeping the legs straight, and then straightens out.

verb (used without object), jack·knifed, jack·knif·ing.

to bend or double over like a jackknife: The prizefighter jackknifed and fell when he was hit in the stomach.

(of a trailer truck) to have the cab and trailer swivel at the linkage until they form a V shape, as the result of an abrupt stop or accident.

(in diving) to perform a jackknife.

to move rapidly at an abrupt angle.

verb (used with object), jack·knifed, jack·knif·ing.

to cause to jackknife: The blow jackknifed the prizefighter.

to cut with a jackknife.

adjective

resembling a jackknife, as in its shape, function, or manner of opening and folding.

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Origin of jackknife

1705–15, Americanism;jack¹ (cf. jockteleg) + knife

Words nearby jackknife

jack-in-office, jack-in-the-box, jack-in-the-green, jack-in-the-pulpit, Jack Ketch, jackknife, jackknife-fish, jack ladder, jackleg, jacklight, jacklighter

How to use jackknife in a sentence

Officials said an initial investigation found that a Ford Fusion was stopped in one of the lanes for “unknown reasons” and a semi-truck struck it in the rear and then jackknifed.
Driver killed in crash with semi-truck along I-270 in Germantown area|Dana Hedgpeth|November 19, 2021|Washington Post
Around the 50-minute mark a jackknife plot turn sends it careering off-road, and it becomes an overburdened movie rather than a nimble one.
The Ice Road Is an Overly Twisty Action Adventure That Has Its Charms, Chief Among Them Liam Neeson|Stephanie Zacharek|June 25, 2021|Time
She cut it with Henry's jackknife into four quarters, and she and Henry took the two crusty ends themselves.
The Box-Car Children|Gertrude Chandler Warner
It was a rather battered jackknife, and Scattergood noticed that one blade had been broken off.
Scattergood Baines|Clarence Budington Kelland

Mr. Blossom drew a jackknife from his pocket and began leisurely to sharpen a pencil.
Scattergood Baines|Clarence Budington Kelland
Then he got up, jerked Mr. Blossom's old jackknife from the post where it had been abandoned, and pocketed it.
Scattergood Baines|Clarence Budington Kelland
"I've heard tell you kin cut real gold like cheese," he said, and opened his jackknife.
Scattergood Baines|Clarence Budington Kelland

British Dictionary definitions for jackknife

jackknife

/ (ˈdʒækˌnaɪf) /

noun plural -knives

a knife with the blade pivoted to fold into a recess in the handle

a former name for a type of dive in which the diver bends at the waist in midair, with his legs straight and his hands touching his feet, finally straightening out and entering the water headfirst: forward pike dive

verb (intr)

(of an articulated lorry) to go out of control in such a way that the trailer swings round at an angle to the cab

to make a jackknife dive

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

jackknife

Origin of jackknife

Words nearby jackknife

Words related to jackknife

How to use jackknife in a sentence

British Dictionary definitions for jackknife