Sapta Sindus which were said to be the root for ‘Hapta Hindu’ were described in the Rigveda mantra as “imamme gange yamune saraswati sutudri stomam sachata parushnya Asiknya Marudvridhe vitastayaarjeekeeye runohya sushomya”. Sapta sindhus are seven rivers called Ganga, Yamuna, Saraswati, Sutudri, Marudvridha, Aarjeekiya and Sushoma. This ‘Sapata Sindhu’ word can be found in Rikmantres (1-35-8) like, ‘astouvyakhyat kakubhah prithivya stree dhanva yojanaa sapta sindhoona’. The people who lived in those areas of sindhu were known as Sindhus and gradually become ‘Hindus’. Since the ‘Hindu’ word is taken by all well known languages, that name only become permanent. That way the Hindu word, even though it got stabilized through ‘Sapta Sindhu’ or indenpendently formed, is a very ancient one and holy one. It has got many meanings and many explanations.