Marranos is a term for Spanish and Portuguese Jews who converted to Christianity, either voluntarily or by Spanish or Portuguese royal coercion, during the fifteenth and sixteenth centuries, but who continued to practice Judaism in secrecy or were suspected of it. They are also called crypto-Jews, the term increasingly preferred in scholarly works over Marranos.
The term specifically refers to the charge of crypto-Judaism, whereas the term converso was used for the wider population of Jewish converts to Catholicism, whether or not they secretly still practised Jewish rites. Converts from either Judaism or Islam were referred to by the broader term of "New Christians".