E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
A large clasp-knife, or combat with clasp-knives. (Snick, Icelandic snikka, to clip; verb, snitte.
to cut. Snee is the Dutch snee, an edge; snijden, to cut.) Thackeray, in his Little Billee, uses the term snickersnee.
One man being busy in lighting his pipe, and another in sharpening his snickersnee.Irving: Bracebridge Hall, p. 462.