Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
2. astus, ūs, m. [Curtius suggests the Sanscr. aksh = to reach, hit, and ὀξύς, swift; and Vanicek, ascia and ἀξίνη, with the idea of sharpness; others ἀσκέω, to practise], adroitness, dexterity; hence, in malam partem, craft, cunning (as a single act, while astutia designates cunning as a habit; until the post-Aug. period found only in the abl., astu, as an adv.; cf. Paul. ex Fest. p. 5 Müll., and Prisc. p. 1012 P.): Satin astu et fallendo callet? Att. Trag. Rel. p. 197 Rib.: Nisi ut astu ingenium linguā laudem et dictis lactem lenibus, id. ib. p. 189: nam doli non doli sunt, nisi astu colas, Plaut. Capt. 2, 1, 30: Sed ut astu sum adgressus ad eas! id. Poen. 5, 4, 53; id. Trin. 4, 2, 123; id. Ep. 4, 1, 19; id. Poen. prol. 111: astu providere, Ter. And. 1, 3, 3: astu rem tractare, id. Eun. 5, 4, 2: Consilio versare dolos ingressus et astu, Incipit haec, Verg. A. 11, 704: ille astu subit, id. ib. 10, 522: aliquem astu adgredi, Tac. A. 2, 64: astus belli, Sil. 16, 32: libertae, Tac. A. 14, 2: oratio, quae astu caret, pondero modo et inpulsu proeliatur, Quint. 9, 1, 20.
In plur.: astus hostium in perniciem ipsis vertebat, Tac. A. 2, 20: praeveniens inimicorum astus, id. ib. 6, 44; 12, 45; Petr. 97: Ulixes nectit pectore astus callidos, Sen. Troad. 527: nunc advoca astus, anime, nunc fraudes, dolos, id. ib. 618: ad insidiarum astus, Gell. 11, 18, 17.