knife: [11] Knife is not a native English word, but a borrowing. It came from Old Norse knífr, which survives also in modern Swedish knif and Danish knif. It can be traced back to a prehistoric Germanic *knībaz, which also produced German kneif ‘cobbler’s knife’, and was borrowed by French as canif ‘knife’, but its previous ancestry is not known.
late Old English cnif, probably from Old Norse knifr, from Proto-Germanic *knibaz (cognates: Middle Low German knif, Middle Dutch cnijf, German kneif), 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 borrowed from Middle English or Norse.
