The word Hindu is very much misunderstood and misused. Many people have no idea how the word originated. In India, some politicians use the the words Hindu and Hindutva with communal overtones either to promote or oppose some ideology or party. To the rest of the world, Hindu and Hinduism refer to a set of people belonging to definite religious system.
The fact is that the BOTH the words “Hindu” and “India” have foreign origin. The word “Hindu” is neither a Sanskrit word nor is this word found in any of the native dialects and languages of India. It should be noted that “Hindu” is NOT a religious word at all. There is no reference of the word “hindu” in the Ancient Vedic Scriptures.
It is said that the Persians used to refer to the Indus river as Sindhu. Indus is a major river which flows partly in India and partly in Pakistan. However, the Persians could not pronounce the letter “S” correctly in their native tongue and mispronounced it as “H.” Thus, for the ancient Persians, the word “Sindhu” became “Hindu.” The ancient Persian Cuneiform inscriptions and the Zend Avesta refer to the word “Hindu” as a geographic name rather than a religious name. When the Persian King Darious 1 extended his empire up to the borders of the Indian subcontinent in 517 BC, some people of the Indian subcontinent became part of his empire and army. Thus for a very long time the ancient Persians referred to these people as “Hindus”. The ancient Greeks and Armenians followed the same pronunciation, and thus, gradually the name stuck.