Source : Webster's Revised Unabridged Dictionary (1913)

Gnarl \Gnarl\, v. i. [imp. & p. p. {Gnarled}; p. pr. & vb. n.
   {Gnarling}.] [From older gnar, prob. of imitative origin; cf.
   G. knarren, knurren. D. knorren, Sw. knorra, Dan. knurre.]
   To growl; to snarl.

         And wolves are gnarling who shall gnaw thee first.
                                                  --Shak.