"Even a brief look at this list indicates that in northern India, by and large, only Sanskritic river names seem to survive.... [he notes that over 90% don't just look IA but] “are etymologically clear and generally have a meaning” [in Indo-Aryan]... [He attributes this unexpectedly large etymological transparency to] “the ever-increasing process of changing older names by popular etymology”. ... [Sindhu might be an] “Indo-Iranian coinage with the meaning ‘border river, ocean’ and fits Paul Thieme's etymology from the IE root *sidh, ‘to divide’”."