.....the word or term Hindu was the term given by the Mohammaden warlords who lived to the west of India, now modern day Persia, Iran, Afghanistan and Pakistan. The term came from the people who live on the other side of the Sindh river, which divides the region running north and south. Those of you who have had association with the followers of Islam will know that they do not propounce the S as we do. The pronounce it with a H sound. Similarly there are other letters like the letter J which they pronounce as Z (jeera to zeera - cummin seeds), etc.
    So those who live across the river Sindh became the Hindus. The real term for what is termed as Hinduism is Sanatan Dharm or the Eternal Religion, or Bhagavat Dharm the religion of Bhagavan - God.

A Hindu perspective.