Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
interpellātor, ōris, m. [interpello], one who interrupts another in speaking, an interrupter, disturber (class.), Auct. Her. 2, 11, 16: ubi se oblectare sine interpellatoribus posset, Cic. Off. 3, 14, 58: matrimoniorum, a seducer, Paul. Sent. 5, 4, 5 Huschke (Dig. 74, 11, 1): cum interpellatores aliis atque aliis causis in jure dicendo (Tiberium) detinerent, Suet. Aug. 97: de pantomimis duobus, … alterum saltorem dixit, alterum interpellatorem, Quint. 6, 3, 65.