Marrano /məˈɹɑːnəʊ/ noun1 •(Judaism, historical) Any of the Sephardi Jews who stayed in Iberia during the Spanish Inquisition, and continued to practice Judaism in secret.In the Portuguese universities, the Marranos had studied logic, physics, medicine and mathematics, but they had no expertise in the more intuitive disciplines of Jewish practice. — 1999 formsMarranos · marranos