What is "tamraparni"

Tamraparni ( Tamil/ Sanskrit) is an ancient name of the river proximal to Tirunelveli of South India and Puttalam of Western Sri Lanka. A toponym, "Tamraparniyan" is eponymous with the socio-economic and cultural history of this area and its people. Movement of people across the Gulf of Mannar during the early Pandyan and Anuradhapura periods, between the Tamilakam coasts of the river and Northwest Sri Lanka, led to the shared application of the name for the closely connected region. The entire island of Sri Lanka itself came to be known in the ancient world as "Tamraparni". It is a rendering of the original Tamil name Tān Poruṇai of the Sangam period, "the cool river Porunai".