The problem of the Iranian hindu- in the mountain name Us.hәndava and Old Indian síndhu- has already been subjected to frequent investigation. Up to 1972 these earlier interpretations are listed in M. Mayrhofer, Kurzgefasstes etymologisches Worterbuch des Altindischen, Lief. 23, 1972, s.v. síndhu-. Accepting a basic meaning ‘flowing water’, connexions have been offered with syandate ‘it flows’ from the time of Yāska till today, assumed as a variant to *syandh-: sindh-, which could be classed as a case of incremental variant -d-with-dh-to syan-, but it has also provoked a doubtful laryngal explanation of -d- with -H-; or assuming a connexion with Old Indian sedh-: sidh-‘to repel’ a doubtful meaning ‘boundary’ has been offered.