The word “Hindu” is not Urdu. It doesn't come from Farsi. Farsi (New Persian) language is not more than 1300 years old. The word Hindu is older than Farsi. It was already mentioned in Zend Avesta of Zoroastrians written in the Avestan language which is more than 3000 years old.
In the inscriptions of the Achaemenid empire (300 BC), the word “Hidu” is used for India, the word “Hida” is used for Sind, and the word “hiduya” is used to refer to a person of Sind. In Zoroastrian scripture word, Hindu is used for Sindu.
Vijaynagara empire inscription always calls their kings “Hindu Raya Suratan”. Maharana Kumbha's inscriptions call him HinduKar. Chhatrapati Shivaji Maharaj also used the Hindu word proudly and founded Hindavi Swarajya.
As per Vriddhi-Smriti, a Hindu is one who shuns violence but is also capable of destroying anarchic elements, a protector of Vedas and cattle.