Although I am also learning Italian (so please feel free to answer in Italian, it will help me learn) I encountered this word in a different context: a musical score.
In the second movement of Boulez’ first sonata he writes “molto spizando” as an indication how a specific bar should be played.
I checked all the dictionaries I could get my hands on (some very respectable musical dictionaries but also Treccani among others) but the closest word I can find is the verb “spizzicare”. To my knowledge there is no way to form “spizando” from spizzicare, only “spizzicando”. A form of spizzicare would also be unexpected in this context.
Does this word exist at all or did Boulez invent it for this sonata?