noun, plural jack·knives.
verb (used without object), jack·knifed, jack·knif·ing.
verb (used with object), jack·knifed, jack·knif·ing.
Origin of jackknife
Examples from the Web for jackknife
Historical Examples of jackknife
Robert drew a jackknife from his pocket, and did as he was bidden.Brave and Bold
The black strips at the end of each nail, Martin pared off with his jackknife.Dust
Mr. and Mrs. Haldeman-Julius
He took out his jackknife, and reaching over, severed the traces.Cap'n Eri
Joseph Crosby Lincoln
Then he pulled out his jackknife and felt its sharp edge with his thumb.The Tale of Timothy Turtle
Arthur Scott Bailey
He carried a whetstone, on which he was sharpening his jackknife.Little Prudy