Ayyanar (IAST: Aiyaṉār, ஐயனார்) is a Hindu deity venerated in South India and Sri Lanka. His worship is prevalent among the Dravidian peoples. Some studies suggest that Ayyanar may have also been worshipped in Southeast Asian countries in the past. He is primarily worshipped as one of the guardian folk deities of Tamil Nadu. The temples of Ayyanar in the countryside are usually flanked by gigantic and colourful statues of him and his companions riding horses or elephants. The Tamil word Ayyanār is derived from the root word Ayya, a honorific used in a Tamil language to designate respected one. Some people propose that Aryan could be the Sanskrit version of Tamil word Aiyyan which means the same. There is a well known temple dedicated to Sastha situated in a village of Kerala, called "Aryankavu". Another name of Ayyanar, Sastha, meets the same dispute. Although he appears as Sastha in Sanskrit scriptures, ancient Tamil records mention him as Chattan (சாத்தன், Cāttaṉ). Though Śāstā is the term especially used to indicate Ayyanar nowadays, there are two other deities known in the same name. Buddha is also called Sastha and Brahma-Śāstā is another name for Murugan. Sastha is a generic Sanskrit term for a teacher. There are very few pieces of evidence to reconstruct the origin and development of Ayyanar. Since Sastha is the synonym of Buddha, some researchers assume Chattan could have entered the Tamil country with Buddhism. The earliest references to Ayyanar were discovered in the hero stones of hunting chieftains from Arcot, Tamil Nadu dated back to the 3rd century C.E. The phrase in the inscriptions which could be translated into "Ayyanappan; a shrine to Cattan" confirms that Ayyan and Chattan were the names of a single deity. A rock carving of a man and horse in the Isurumuniya Buddhist temple of Sri Lanka, is identified with Ayyanar. Sinhala Buddhists of Sri Lanka praise him in the form of a folk deity called Ayyanayake to the date. Sastha started to appear in Sanskrit sources from the 7th century CE after Brahmanda Purana.