‖ sereˈnissimo,a.andn.Obs. Pl. -i, also -o's. [It.: see prec.] =prec. 1665Sir T. Herbert Trav. (1677) 140 The Tiara which was worn by Serenissimo's.1672tr.Nieremberg's Temporal & Eternal iii. vi. 272 (Stanf.) How many are called Serenissimi, who have their understanding darkened.