Words related to knife

Middle English spelling of a common Germanic consonant-cluster (in Old English it was graphed as cn-; see K). The sound it represented persists in most of the sister languages, but in English it was reduced to "n-" in standard pronunciation by 1750, after about a century of weakening and fading. It was fully voiced in Old and Middle English.
butcher-knife (n.)
1822, from butcher (n.) + knife (n.). Butcher's knife is attested from 1714.
case-knife (n.)
"knife carried in a sheath," 1704, from case (n.2) + knife (n.).
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. 

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.

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.).