Lewis & Short

vĕtĕrātōrĭus, a, um, adj. [veterator, II. A.], crafty. cunning, sly (Ciceronian): nihil ab isto tectum, nihil veteratorium exspectaveritis: omnia aperta, omnia perspicua reperientur, Cic. Verr. 2, 1, 54, § 141; so, ratio dicendi, id. Brut. 75, 261.
* Adv.: vĕtĕrātōrĭē, craftily, cunningly, slyly: dicere (with acute), Cic. Or. 28, 99.