Lewis & Short

Drūsus, i, m., a well-known Roman surname in the Livian family, first assumed by the Livius who slew the Gallic general Drausus, Suet. Tib. 3.
Esp.

    1. 1. M. Livius Drusus, uncle of Cato Uticensis, murdered by Q. Varius, Cic. Arch. 3, 6; Vell. 2, 13.
    2. 2. Claudius Drusus Nero, son of Tib. Claudius Nero and Livia Drusilla, father of Germanicus, the theme of Hor. C. 4, 4; Suet. Claud. 1; Tac. A. 1, 33.
      Hence, Drūsĭānus, a, um, adj.: fossa, Tac. A. 2, 8, or Drūsīnus, a, um, adj.: fossae, a canal on the Lower Rhine, constructed by Drusus, the son of Livia, Suet. Claud. 1.
      Drūsilla, ae, f., the name of several females of the Livian family.
      Esp.
    1. 1. Livia Drusilla, the second wife of Augustus, v. Livius.
    2. 2. Drusilla, daughter of Drusus Germanicus, Tac. A. 6, 15; Suet. Calig. 7; 24 al.