Con·ver·so 
(kən-vĕrsō)
(kən-vĕrsō)n. pl. Con·ver·sos
A Spanish or Portuguese Jew who converted outwardly to Christianity in the late Middle Ages so as to avoid persecution or expulsion, though often continuing to practice Judaism in secret.
[Spanish, a convert, from converso, converted, from Medieval Latin conversus, from Latin, past participle of convertere, to turn around, convert; see CONVERT.]