Source : Webster's Revised Unabridged Dictionary (1913)

Grizzle \Griz"zle\, v. t. & i.
   To make or become grizzly, or grayish.

         Hardship of the way such as would grizzle little
         children.                                --R. F.
                                                  Burton.

         I found grizzling man whom men addressed as Collins
         Bey.                                     --Pall Mall
                                                  Mag.

Grizzle \Griz"zle\, v. i. & t. [Etym. uncertain.]
   To worry; to fret; to bother; grumble. [Prov. Eng.] `` Don't
   sit grizzling there.'' --Charles Reade.

Grizzle \Griz"zle\, n. [F. gris: cf. grisaille hair partly gray,
   fr. gris gray. See {Gris}, and cf. {Grisaille}.]
   Gray; a gray color; a mixture of white and black. --Shak.

Source : WordNet®

grizzle
     n : a grey wig
     v 1: be in a huff; be silent or sullen [syn: {brood}, {stew}]
     2: complain whiningly [syn: {whine}, {yammer}, {yawp}]