Definition of TZITZIT. : the fringes or tassels worn on traditional or ceremonial garments by Jewish males as reminders of the commandments of Deuteronomy 22:12 and Num 15:37–41.efinition of TZITZIT. : the fringes or tassels worn on traditional or ceremonial garments by Jewish males as reminders of the commandments of Deuteronomy 22:12 and Num 15:37–41.