Lewis & Short

Caesōnĭus, a, name of a Roman gens.
So,

  1. I. M. Caesonius, œdile with Cicero, Cic. Att. 1, 1, 1; 1, 12, 11; id. Verr. 1, 10, 29.
  2. II. Caesonius Paetus, consul under Nero, Tac. A. 14, 29.
    Hence, Caesōnĭānus, a, um, adj., Col. 1, 4, 1.
  3. III. Milonia Caesonia, mistress and afterwards wife of Caligula, Suet. Calig. 25; Juv. 6, 616.