ADVERB (3)

1. (of the elements) in a wild and stormy manner;
- Example: "winds were blowing furiously"

2. in a manner marked by extreme or violent energy;
- Example: "the boys fought furiously"
- Example: "she went peddling furiously up the narrow street"

3. in an impassioned or very angry manner;
- Example: "she screamed furiously at her tormentors"

The Collaborative International Dictionary of English v.0.48:

Furious \Fu"ri*ous\, a. [L. furiosus, fr. furia rage, fury: cf.
   F. furieux. See Fury.]
   1. Transported with passion or fury; raging; violent; as, a
      furious animal.
      [1913 Webster]

   2. Rushing with impetuosity; moving with violence; as, a
      furious stream; a furious wind or storm.

   Syn: Impetuous; vehement; boisterous; fierce; turbulent;
        tumultuous; angry; mad; frantic; frenzied. --
        Fu"ri*ous*ly, adv. -- Fu"ri*ous*ness, n.
        [1913 Webster]

WordNet (r) 3.0 (2006):

furiously
    adv 1: (of the elements) in a wild and stormy manner; "winds
           were blowing furiously"
    2: in a manner marked by extreme or violent energy; "the boys
       fought furiously"; "she went peddling furiously up the narrow
       street"
    3: in an impassioned or very angry manner; "she screamed
       furiously at her tormentors"