Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
pĕremptor (pĕremtor), ōris, m. [perimo], a destroyer, slayer, murderer (postclass.): incluti regis, Sen. Oedip. 221: mariti mei cruentis, App. M. 8, p. 207, 16; cf.: puer ille peremptor meus, i. e. who has playued me almost to death, id. ib. 7, p. 198, 21.
Absol., Prud. Ham. praef. 19; Ambros. Inst. Virg. 7, 4, 9; Vulg. 2 Macc. 4, 16.