Jackknife may refer to: *

Pocketknife A pocketknife (also spelled as pocket knife) is a knife with one or more blades that fold into the handle. They are also known as jackknives, folding knives, Everyday carry, EDC knife, or may be referred to as a penknife, though a penknife may a ...

or jackknife, a compact, foldable knife *

Jackknife Bar Jackknife Bar, or simply Jackknife, was a bar in Portland, Oregon. The 4,000-square-foot cocktail bar was housed in the Sentinel Hotel, before closing in May 2020, during the COVID-19 pandemic. Description The interior featured a 50-seat, 65-foot ...

, Portland, Oregon, U.S. *

Jackknifing Jackknifing is the folding of an articulated vehicle so that it resembles the acute angle of a folding pocket knife. If a vehicle towing a trailer skids, the trailer can push the towing vehicle from behind until it spins the vehicle around and ...

, a type of crash with articulated vehicle combinations

Film and television

* ''

Jacknife ''Jacknife'' is a 1989 American film directed by David Jones and starring Robert De Niro, Ed Harris and Kathy Baker. The film focuses on a complex tension between people in a close family relationship. Stephen Metcalfe, on whose play ''Strang ...

'', a 1989 American film by David Jones * "Jack Knife", an episode of ''NCIS'' * Jackknife, a character on ''

Superjail! ''Superjail!'' is an American adult animated television series created by Christy Karacas, Stephen Warbrick and Ben Gruber for Cartoon Network's late night programming block, Adult Swim. It follows the events that take place in an unusual pr ...

Athletics and sports

Jackknife (exercise) A jackknife is an abdominal exercise. This exercise is also known as a "V-Up". Jackknife exercises are designed to strengthen the upper and lower abdominal muscles, particularly the transversus abdominis muscle. There are a number of variation ...

, an abdominal exercise * Jackknife, a kicking move involving 540-degree rotation * Jackknife, a type of high dive * Jackknife hold, a pinning move in professional wrestling

Other uses

Jackknife (statistics) In statistics, the jackknife (jackknife cross-validation) is a cross-validation technique and, therefore, a form of resampling. It is especially useful for bias and variance estimation. The jackknife pre-dates other common resampling methods suc ...

, a resampling technique in statistics *

Jackknife clam Jackknife clam is a common name which is used for several species in the genera ''Ensis'' and '' Solen'' within the family Solenidae, species which are found on Atlantic and Pacific beaches of temperate North America. Species in these families are a ...

, common name for several species of bivalve mollusc

Film and television

Athletics and sports

Other uses

See also