Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
† phylarchus, i, m., = φύλαρχος, the chief of a tribe, a prince, emir: phylarchus Arabum, Cic. Fam. 15, 1, 2: Saracenorum, Amm. 24, 2; Sex. Ruf. Brev. 14.