Etymology
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knife (n.)
"hand-held cutting instrument consisting of a short blade and handle," late Old English cnif, probably from Old Norse knifr "knife, dirk," from Proto-Germanic *knibaz (source also of Middle Low German knif, Middle Dutch cnijf, German kneif), a word of uncertain origin. To further confuse the etymology, there also are forms in -p-, such as Dutch knijp, German kneip. French canif "penknife" (mid-15c.) is probably of Germanic origin, perhaps from Frankish. For pronunciation, see kn-.
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knife (v.)
1865, "stab or kill with a knife," from knife (n.). Intransitive meaning "move as a knife does" is from 1920. Related: Knifed; knifing.
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case-knife (n.)
"knife carried in a sheath," 1704, from case (n.2) + knife (n.).
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butcher-knife (n.)
1822, from butcher (n.) + knife (n.). Butcher's knife is attested from 1714.
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clasp-knife (n.)

"knife with one or more blades which fold into the handle," 1743, from clasp (n.) + knife (n.). The thing itself was known to the Etruscans and Romans; it became popular again 17c. 

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pocket-knife (n.)

"knife with a blade or blades which fold into the handle, suitable for carrying in the pocket," 1727; see pocket (n.) + knife (n.).

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penknife (n.)

also pen-knife, "small pocket-knife," early 15c., penne-knif, from pen (n.1) + knife (n.). So called because such small knives were used to make and mend quill pens.

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jack-knife (n.)
also jackknife, "pocket knife larger than a pen-knife," 1711, probably American English, apparently from some sense of jack (n.). Perhaps it originally was associated with sailors. Jackleg, jacklegged was a U.S. colloquial term of contempt from 1839. Scottish dialect had jockteleg (1670s) "large clasp-knife," of unknown origin, also jackylegs, jack-o-legs. As a kind of swimming dive from 1922; as a type of tractor-trailer accident, 1966; both from the notion of folding, as the knife does.
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jack-knife (v.)
1776, "to stab," from jack-knife (n.). Intransitive meaning "to fold or bend" the body is said to date from the time of the American Civil War. The truck accident verbal sense is from 1949. Related: Jackknifed; jackknifing.
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cutlery (n.)

mid-14c., cutellerie, "the cutler's craft, art or trade of knife-making," from Old French coutelerie "cutlery, knife-making" (13c., Modern French coutellerie) "cutting utensils," also "knife-making," from coutel "knife," from Latin cultellus (see cutlass). Meaning "knives and cutting utensils collectively" is from 1836.

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