The Collaborative International Dictionary of English v.0.48:

Scruff \Scruff\, n. [See Scurf.]
   Scurf. [Obs.]
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Scruff \Scruff\, n. [Cf. Scuff.]
   The nape of the neck; the loose outside skin, as of the back
   of the neck.
   [1913 Webster]

WordNet (r) 3.0 (2006):

scruff
    n 1: the back side of the neck [syn: nape, scruff, nucha]