An Arab (Arabic: عربي) is a member of a complexly defined ethnic group who identifies as such on the basis of one or all of either geneaological, political, or linguistic grounds.
The Arabic language and culture began to spread in the Middle East in the 2nd century with genealogically Arab Christians such as the Ghassanids, Lakhmids, and Banu Judham, and even earlier Arab Jewish tribes. Widespread proliferation of Arab language, culture and identity in the Middle East and North Africa, however, did not begin until after the advent of Islam in the 7th century and the ensuing Arab Muslim expansion. The early conquests of successive Islamic Arab empires resulted in the Arabization and cultural assimilation of the region's other indigenous Semitic and non-Semitic peoples of non-Arabian origin, often but not always together with their Islamization. With time, the label Arab expanded beyond a pure geneaological definition to come to be associated with Arabized populations of countries in North Africa and the Middle East. This latter expanded definition is contested by many it would encompass, regardless of religious heritage, including Muslims.