The name Punjab is

The name Punjab is a xenonym/exonym and the first known mention of the word Punjab is in the writings of Ibn Batuta, who visited the region in the 14th century.  The term came into wider use in the second half of the 16th century, and was used in the book Tarikh-e-Sher Shah Suri (1580), which mentions the construction of a fort by "Sher Khan of Punjab". The first mentioning of the Sanskrit equivalent of 'Punjab', however, occurs in the great epic, the Mahabharata (pancha-nada 'country of five rivers').