Source : Webster's Revised Unabridged Dictionary (1913)

Bunch \Bunch\, v. i. [imp. & p. p. {Bunched}; p. pr. & vb. n.
   {Bunching}.]
   To swell out into a bunch or protuberance; to be protuberant
   or round.

         Bunching out into a large round knob at one end.
                                                  --Woodward.