Lewis & Short

Nĭgĭdĭus, ii, m.:

  1. I. P. Nigidius Figulus, a celebrated Roman scholar, a contemporary of Cicero and Cæsar, the composer of several grammatical works, Gell. 19, 14, 1; cf. id. 4, 9, 1 sqq.
    Hence,
  2. II. Nĭgĭdĭānus, a, um, adj., of Nigidius: commentationes, Gell. 18, 4, 11; 19, 14, 3.