Its name is commonly believed to have been derived from the Tamil words aaru (River) + kaadu (forest). However, arkaadu meant 'a forest of fig trees'. Jainism was flourishing in this part of Tamil Land who were otherwise known as Arugar most probably corrupted form of Arhants or the perfected souls. The word Arugar is found in many ancient literary works and places dominant with arugars were related to them viz Arakonam, Arumbakkam, Aruvur, etc. Not far away from present day Arcot (Anglicized form of Aarkaadu) there is a place called Arungundram. Hence Arcot or Aarkaadu would have derived its name from Arugarkaadu.