Meaning & use
jackknife
Last updated
A large pocketknife with a blade that folds into the handle.
See it in a sentence
He carried a jackknife on every camping trip for cutting rope and whittling wood.
The scout used his jackknife to cut through the tangled fishing line.
A note on using this word
As a verb, 'jackknife' most often describes a semi-truck's trailer swinging dangerously out of line with its cab, usually due to sudden braking on a slippery road.
Words with a similar meaning
pocketknife
Choose a synonym to suit the sentence. Meanings can overlap without being identical.
Another way to use it
2. verb
To fold sharply at a hinge point, as when a trailer truck's cab and trailer bend into each other.
The truck jackknifed on the icy highway, blocking both lanes of traffic.
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