Hindu Kush

First recorded in 1820–30; possibly from Persian koš, a derivative of the verb koštan “to kill,” the phrase meaning “Hindu killer” (from when slaves being transported from the Indian subcontinent to Central Asia died in the harsh climate of these mountains); possibly from Persian Hindūkuš, Hendukoš “Mountains of the Indus / of India,” which, in some 19th-century reports was also interpreted in a popular etymology as a compound of Hendu and koš “Hindu-slayer”