have been Dravidian in origin, on the basis that Tamil and Malayalam "hardly ever substitute (Retroflex approximant) 'ɻ' peculiarly Dravidian sound, for Sanskrit -'l'-." He suggests that the name "Eelam" came from the Dravidian word "Eelam" (or Cilam) meaning "toddy", referring to the palm trees in Sri Lanka, and later absorbed into Indo-Aryan languages. This, he says, is also likely to have been the source for the Pali '"Sihala". The Dravidian Etymological Dictionary, which was jointly edited by Thomas Burrow and Murray Emeneau, marks the Indo-Aryan etymology with a question mark. Karthigesu Indrapala updated his theory in 2005 and claims that Eela, the stem of Eelam, is attested in Sri Lanka for centuries before the common era as a name of an ethnic group, and eventually it came to be applied to the island as Eelam. He also believes that the name of the island was applied to the popular coconut tree or vice versa in Tamil. He believes the early native names for the present Sinhalese ethnic group, such as Hela, are derivations of Eela, which was Prakritized as Sihala and eventually Sanskritized as Simhala in the 5th century CE. Other theories Peter Schalk, a professor of theology from University of Uppsala, concludes that it is a word used exclusively for toddy beginning from the common era up until the medieval period. Another theory based on archeological evidence suggests the word is a Tamil word which originated from South India. Also the Tamil meaning of "Eelam" is postulated to be homeland. The Tamil lexicons (Nika'ndu), Thivaakaram, Pingkalam and Choodaama'ni, dating from c. 8th century CE, equate the word Eezham with Chingka'lam (the Sinhala country). Eelam is also the Tamil name for the spurge (a plant), toddy (an intoxicant) and gold. Cognate terms Ancient ethnic group Eela and Eelavar are etymologically related to Eelam. The stem Eela is found in Prakrit inscriptions dated to 2nd century BCE in Sri Lanka in terms such as Eela-Barata and Eela-Naga, proper names. The meaning of Eela in these inscriptions is unknown although one could deduce that they are either from Eela, a geographic location, or were an ethnic group known as Eela. South Indian caste Eelavar in South Indian medieval inscriptions refer to the caste or function of toddy-drawers, drawn from the Dravidian word for palm tree toddy, Eelam. From the 19th century onwards, sources appeared in South India regarding a legendary origin