Source : Webster's Revised Unabridged Dictionary (1913)

Gesticulate \Ges*tic"u*late\, v. i. [imp. & p. p.
   {Gesticulated}; p. pr. & vb. n. {Gesticulating}.] [L.
   gesticulatus, p. p. of gesticulari to gesticulate, fr.
   gesticulus a mimic gesture, gesticulation, dim. of gestus
   gesture, fr. gerere, gestum, to bear, carry, peform. See
   {Gestic}.]
   To make gestures or motions, as in speaking; to use postures.
   --Sir T. Herbert.

Source : WordNet®

gesticulating
     adj : making gestures while speaking; "her gesticulating hands and
           arms made words almost unnecessary"