Adi Dravidar is term used by the state of Tamil Nadu

Tamil Nadu

Tamil Nadu is one of the 28 states of India. Its capital and largest city is Chennai. Tamil Nadu lies in the southernmost part of the Indian Peninsula and is bordered by the union territory of Pondicherry, and the states of Kerala, Karnataka, and Andhra Pradesh...

 in India to denote Dalits. It means Original natives or indigenous people of Dravida land . The term was coined by Tamil social activist Periyar Ramasami who worked against casteism and division among the people based on castes. Many Adi Dravidas have converted to Christianity

Christianity

Christianity is a monotheistic religion based on the life and teachings of Jesus as presented in canonical gospels and other New Testament writings...

, Islam

Islam

Islam . The most common are and .   : Arabic pronunciation varies regionally. The first vowel ranges from ~~. The second vowel ranges from ~~~...

 and Buddhism

Buddhism

Buddhism is a religion and philosophy encompassing a variety of traditions, beliefs and practices, largely based on teachings attributed to Siddhartha Gautama, commonly known as the Buddha . The Buddha lived and taught in the northeastern Indian subcontinent some time between the 6th and 4th...

.

Dravidian refers both to Dravidian languages

Dravidian languages

The Dravidian language family includes approximately 85 genetically related languages, spoken by about 217 million people. They are mainly spoken in southern India and parts of eastern and central India as well as in northeastern Sri Lanka, Pakistan, Nepal, Bangladesh, Afghanistan, Iran, and...

, a group of languages, and to the Dravidian people, who speak them. Almost all of the South Indians speak Dravidian languages.