Passage 4

When they first arrived in Europe over 500 years ago, the Roma were called Gypsies in the mistaken belief that they had come from Egypt. The true origins of the Roma remained a mystery until the late 18th century, when European linguists discovered connections between the Romani language and certain dialects spoken in northwestern India. The world population of Roma is difficult to establish with any certainty. Estimates suggest that there are approximately 12 million Roma worldwide. About 8 million Roma live in Europe, and they make up that continent’s largest minority population. The Roma are divided into groups sometimes referred to as nations or tribes. These divisions generally reflect historical patterns, of settlement in different geographic areas. Although historically looked at as wanderers, the vast majority of modern Roma live in settled communities. Because the Roma are widely settled, their culture and social organization vary considerably. An important characteristic everywhere, however, is a strong, sense of Stoup identity, Romani culture stresses the sacredness of its own traditions in opposition to those of the outside world. Contact with non-Roma is regarded as potentially polluting. Another unifying force is their language, Romani, which consists of a number of dialects belonging to the Indo-Iranian branch of the Indo-European languages. Most Roma speak some form of Romani. Others speak dialects of local languages with extensive borrowings from Romani. Romani is primarily a spoken rather than written language. Until recent years most Roma were illiterate, and illiteracy rates remain high in most Roma communities.

"Contact with non-Roma is regarded as potentially polluting." probably means ______.