Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
oscen, ĭnis, m. (but f. ap. Varr. L. L. 6, 7, 67; Plin. 10, 19, 22, § 43) [obscen, from obs-cano], a singing-bird, esp. in the auspices; a divining-bird, from whose notes auguries were taken (e. g. the raven, crow, owl): aves aut oscines sunt, aut praepetes: oscines, quae ore futura praedicunt; praepetes, quae volatu augurium significant, Serv. Verg. A. 3, 361; Cic. Fam. 6, 6, 13: oscinem corvum prece suscitabo, Hor. C. 3, 27, 11; Plin. 10, 19, 22, § 43; App. de Deo Soc. p. 45, 29: Phoebeius, i. e. the crow metamorphosed by Phœbus, Aus. Idyll. 11, 15.