frāternitas, ātis, f. fraternus, brotherhood, fraternity (post-Aug. and very rare): fraternitatis vinculum, Lact. 5, 6, 12: Aedui soli Gallorum fraternitatis nomen cum populo Romano usurpant, Tac. A. 11, 25; Vulg. Rom. 12, 10; Quint. Decl. 16, 2 (cf. frater, Il. A. fin., and fraternus, Il.).