Lewis & Short

illittĕrātus or illītĕrātus (inl-), a, um, adj. [in-litteratus].

  1. I. Unlettered, illiterate, uneducated, unlearned (class.): quem cognovimus virum bonum et non illitteratum, Cic. de Or. 2, 6, 25: rusticus illitteratusque, Quint. 2, 21, 16: illitteratum dicimus non ex toto rudem, sed ad litteras altiores non perductum, Sen. Ben. 5, 13, 4; cf. also of one who cannot read, Col. 1, 8, 4.
    Of things, unlearned, unpolished, inelegant: incidunt in sermone vario multa, quae fortasse illis cum dixi nec illitterata nec insulsa esse videantur, Cic. Fam. 9, 16, 4: nervi, Hor. Epod. 8, 17: scribo plurimas sed illitteratissimas litteras, Plin. Ep. 1, 10, 9; 2, 3, 8.
  2. II. Unwritten, i. e. not drawn up in writing, = ἄγραφος (post-class. and very rare): tacito illitteratoque Atheniensium consensu, Gell. 11, 18, 4; cf.: illitterata pax est, quae litteris comprehensa non est, Paul. ex Fest. p. 113 Müll.
  3. III. Inarticulate: sonitus, interjections, Prisc. 1024 P.: vox, id. 537 P.