Adi Dravidar is term used by the state of Tamil Nadu 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, Islam and Buddhism.
Dravidian refers both to Dravidian languages, a group of languages, and to the Dravidian people, who speak them. Almost all of the South Indians speak Dravidian languages.