Lewis & Short

Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.

Săbellĭus, i, m., an elder of the Christian Church at Rome, and afterwards at Ptolemais, in the third century, the founder of the heretical sect of Sabellians, Prud. Apoth. 178.
Hence, Săbellĭāni, ōrum, m., the followers of Sabellius, Sabellians, Ambros. Fid. 5, 13, 162; id. Incarn. Sacr. 2, 8.