Avadi () is a suburb of Chennai within Chennai Metropolitan Area limit, located in the Thiruvallur district of Tamil Nadu, India. It is a municipal corporation west of Chennai, about from Chennai Central Railway Station. It is surrounded by major defence establishments and is home to various universities and engineering colleges. The city is served by Avadi Railway Station of the Chennai Suburban Railway. As of 2011, Avadi had a population of 345,996, which is 10th most populous place in Tamil Nadu. It is home to the Heavy Vehicles Factory (HVF), Ordnance Factory Board (ODF) which houses Engine Factory and Combat Vehicles Research and Development Establishment (CVRDE). The lake in Avadi was known as Paaleripattu, which is now found only in very old land documents. Etymology The exact origin of the name 'Avadi' is not known. One version has it that it is the combination of "Aa" (meaning cow) and "Adi or gudi (kudi)" (meaning place in Tamil), indicating that the place had many cows. AVADI stands for Armed Vehicles Ammunition Depot of INDIA One of the more popular theories about the origin of the name is that it is an acronym for "Armoured Vehicles and Ammunition Depot of India". However, this is most likely a backronym invented more recently. The entity "Armoured Vehicles and Ammunition Depot of India" does not appear in any British records. Several British documents from the 19th century refer to the place as "Avady", which doesn't match the widely circulated acronym theory. The name Avadi (Avady) was already in use by 1856, when the first public railway was opened in the Madras Presidency. This predates the transfer of the Madras Presidency's arsenal from Fort St. George, India in the city of Madras, to Avadi, which was done sometime after 1870, which contradicts the popular acronym theory. History The neighbourhood is part of the "auto belt" that developed when the automobile industry developed in Madras, primarily in the city's industrial north and west regions, in the early post-World War II years. The famous session of the Indian National Congress was held at Avadi on 10 January 1955. This historical meet emphasised the importance of socialism and its impact on social development. Jawaharlal Nehru with Morarji Desai and other Congress leaders at the AICC session declared that a socialistic pattern of society was the goal of the Congress. Geography Avadi is located at . It covers an