Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
emptor (emt-), ōris, m. [emo], a buyer, purchaser (cf.: negotiator, mercator, caupo, institor), Plaut. Poen. 1, 2, 128 sq.; id. Pers. 4, 4, 31; Cic. Off. 3, 12, 51; id. Phil. 2, 38; id. Caecin. 7, 19; Hor. S. 1, 2, 88; id. Ep. 2, 2, 167 et saep.; cf., on the laws affecting him, the authorities cited under emptio: pretiosus dedecorum, i. e. who buys them dearly (= magno pretio emens), Hor. C. 3, 6, 32: familiae, the imaginary purchaser of an inheritance per aes et libram, Suet. Ner. 4 Bremi; cf. Rein’s Privatr. p. 375.