Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
Ărātēus (Ărātī-), a, um, adj., = Ἀράτειος, of or belonging to the Greek poet Aratus, Aratean: lucernae, Cinna ap. Isid. Orig. 6, 12.
Hence, absol.: nostra quaedam Aratea, i. e. the Φαινόμενα of Aratus, translated by Cicero into Latin, Cic. Div. 2, 5, 14 B. and K.; of this translation we still possess large portions; v. Cic. Orell. IV. pp. 1014, 1033: carminibus Arateis, Cic. N. D. 2, 41, 104.