The etymology of "Delhi" is uncertain, but many possibilities exist. The most common view is that its eponym is Dhillu or Dilu, a king of the Mauryan dynasty and named the city after himself. The Hindi word dhili ("loose") was used by the Tuar Rajputs to refer to the city because the Iron Pillar built by Raja Dhava had a weak foundation and was replaced. The coins in circulation in the region under the Rajputs were called dehliwal. Some other historians believe that the name is derived from Dilli, a corruption of dehleez or dehali—Hindi for 'threshold'—and symbolic of city as a gateway to the Indo-Gangetic Plains. Another theory suggests that the city's original name was Dhillika.