Source : Webster's Revised Unabridged Dictionary (1913)

Vociferous \Vo*cif"er*ous\, a. [Cf. F. vocif[`e]re.]
   Making a loud outcry; clamorous; noisy; as, vociferous
   heralds. -- {Vo*cif"er*ous*ly}, adv. -- {Vo*cif"er*ous*ness},
   n.

Source : WordNet®

vociferously
     adv : in a vociferous manner; "he complained vociferously"