1. In a physically fierce manner
   "they fought fiercely"
   - ferociously 
2. In an emotionally fierce manner
   "she was fiercely proud of her children"

See also: fierce

• unnumerable
• unobjectionable
• unobjective
• unobligated
• unobliging
• unobservable
• unobservant
• unobserved
• unobserved fire
• unobstructed
• unobtainable
• unobtrusive
• unobtrusively
• unobtrusiveness
• unobvious
• unoccupied
• unoffending
• unofficial
• unofficially
• unoiled
• unopen
• unopened
• unopposable
• unopposed
• unordered