wildness vs fierceness

wildness and fierceness both are nouns.

Word	Noun	Adjective	Verb	Adverb
wildness	Yes	No	No	No
fierceness	Yes	No	No	No

As nouns, wildness and fierceness are synonyms defined as:

Other synonyms of wildness include ferocity, furiousness, fury, vehemence, violence.

wildness (noun)	fierceness (noun)
an intractably barbarous or uncultivated state of nature	the property of being wild or turbulent
an unruly disposition to do as one pleases
the property of being wild or turbulent
a feeling of extreme emotional intensity