Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
appellātor, ōris, m. [2. appello], one that appeals, an appellant, * Cic. Verr. 2, 4, 65 fin.; Paul. Sent. 5, 4 fin.; Cod. Th. 11, 31, 3.