Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “jackknife”

jackknife

verb [I] uk   /ˈdʒæk.naɪf/ us  
If a truck that has two parts jackknifes, one part moves around so far towards the other part that it cannot be driven: The oil tanker jackknifed after skidding on the ice.

jackknife

noun [C] uk   /ˈdʒæk.naɪf/ (plural jackknives) us  
a large knife with a blade that folds into the handle
(Definition of jackknife from the Cambridge Advanced Learners Dictionary & Thesaurus © Cambridge University Press)
What is the pronunciation of jackknife?
Add Cambridge dictionaries to your browser to your website

Definitions of “jackknife” in other dictionaries

Word of the Day

first:

(a person or thing) coming before all others in order, time, amount, quality, or importance

Word of the Day

Countability – grammar codes

by Dom Glennon​​,
November 26, 2014
Advices and informations Have you ever noticed strange codes in square brackets on entries in Cambridge Dictionaries Online and wondered what they mean? These are grammar codes, giving you a brief summary of how that word behaves grammatically. More information can be obtained by hovering your cursor over the code, and there’s

Read More 

ped-text verb

November 24, 2014
to text someone while walking I’m ped-texting, I’m looking down at my phone, 75 percent of the time.

Read More