Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
† martyr, yris, comm., = μάρτυρ, a witness; esp. one who by his death bears witness to the truth of the Christian religion, a martyr (eccl. Lat.): salvete flores Marty rum, Prud. Cath. 12, 125; Vulg. Apoc. 17, 6
In fem.: Perpetua, fortissima martyr, Tert. Anim. 55.