Nick or Old Nick is a well-known appellation of the Devil. The name appears to have been derived from the Dutch Nikken, the devil, which again comes from the Anglo-Saxon nac-an, to slay–for as Wachter says the devil was «a murderer from the beginning.» In the northern countries there is a river spirit named «Neck,» «Nikke,» or «Nokke» of the same nature as the water Kelpie, and the Merman of Triton. A.G.H.
Source: 81, 296.