FIERCELY

ferociously, fiercely

(adverb) in a physically fierce manner; “silence broken by dogs barking ferociously”; “they fought fiercely”

fiercely

(adverb) in an emotionally fierce manner; “she was fiercely proud of her children”

Source: WordNet® 3.1

Etymology

Adverb

fiercely (comparative fiercelier or more fiercely, superlative fierceliest or most fiercely)

In a fierce manner.

Source: Wiktionary

FIERCE

Fierce, a. [Compar. Fiercer; superl. Fiercest.] Etym: [OE. fers, fiers, OF. fier, nom. fiers, fierce, savage, cruel, F. fier proud, from L. ferus wild, savage, cruel; perh. akin to E. bear the animal. Cf. Feral, Ferocity.]

1. Furious; violent; unrestrained; impetuous; as, a fierce wind. His fierce thunder drove us to the deep. Milton.

2. Vehement in anger or cruelty; ready or eager to kill or injure; of a nature to inspire terror; ferocious. "A fierce whisper." Dickens. "A fierce tyrant." Pope. The fierce foe hung upon our broken rear. Milton. Thou huntest me as a fierce lion. Job. x. 16.

3. Excessively earnest, eager, or ardent.

Syn.

– Ferocious; savage; cruel; vehement; impetuous; barbarous; fell. See Ferocious.

– Fierce"ly, adv.

– Fierce"ness, n.

Source: Webster’s Unabridged Dictionary 1913 Edition