Baretti: A dictionary of the English and Italian languages
Fétt-a, s. f. dim. Fétt-erélla, Fétt-ína, Fétt-olína, Fétt-úccia,Fétt-úzza , aug. Fétt-óne,
1. slice, cut. Una — di pane,a slice of bread; 2. bit, small portion of any thing; 3. tape, ferret. Far — di se, to prostitute one's self, abandon one's self.
Florio: a worlde of wordes, or most copious, dictionarie in Italian and English
fetta: a slice, a collop, a shiuer, a skin or cut of any meat or of bread.