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 literal meaning of the word "Hindko" is "Mountains of the Indus". 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.