It can be used in context as a noun and as a verb.
N. - Fionn(sing.)(m): A man of great street credibility and respect; one who needs to beat off women with a stick to remain unraped.
ADJ. - Fionn (-icious(-ly)): Word describing the innate attractiveness of a male individual that one had never met but heard of in passing.
Lady friend/ Ho: OH, MY, GOD... I don't think I've ever had a Fionn like you do something to me that so...Fionniciously..mmmm
Male Friend: Hey man, I heard one of the bitches thinks yo shit is Fionnicious