Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
Ămūlĭus, i, m., = Ἀμούλιος, son of Procas, king in Alba, who expelled his brother Numitor, and ordered his grandsons Romulus and Remus to be thrown into the Tiber; hence, dirus, Ov. F. 4, 53; cf. Liv. 1, 3 sq.: injustus, Ov. M. 14, 772 al.