Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
Pacōnĭus, i, m., the name of a Roman gens. So M. Paconius, Cic. Mil. 27, 74; another M. Paconius, Suet. Tib. 61; Tac. A. 3, 66.