WHAT DID HINDUSTAN STAND FOR IN MEDIEVAL TIMES?

Hi

Ancient name for river Indus was Sindhu. So the term was referred to denote those who lived in the Indian subcontinent on or beyond the “Sindhu” river. 

The Greeks found difficulty in pronouncing S, thus making it easier for the Greeks to pronounce it as Hindu. The region where the people on or beyond Hindu was named as Hindustan or the land of Hindus.

Cheers!