savagery vs fierceness

savagery and fierceness both are nouns.

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

As nouns, fierceness is a hypernym of savagery; that is, fierceness is a word with a broader meaning than savagery:

Other hypernyms of savagery include ferocity, furiousness, fury, vehemence, violence, wildness.

savagery (noun)	fierceness (noun)
a brutal barbarous savage act	the property of being wild or turbulent
the trait of extreme cruelty
the property of being untamed and ferocious