Source : Webster's Revised Unabridged Dictionary (1913)

Scruff \Scruff\, n. [See {Scurf}.]
   Scurf. [Obs.]

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

Source : WordNet®

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