Original: The word "Hind" is the Persianised reference to the regions associated with the Indus River immediately to the east of Persia and "Ko" means mountainsEncyclopædia Britannica Eleventh Edition - Kohistan .
Simplified: The word "Hind" is the Persianised reference to the regions associated with the Indus River immediately to the east of Persia and "Ko" means mountains.