Khwarezm ( /kwəˈrɛzəm/) or Chorasmia ( /kəˈræzmiə/) is a large oasis region on the Amu Darya river delta in western Central Asia, which borders to the north the (former) Aral Sea, to the east the Kyzylkum desert, to the south the Karakum desert and to the west the Ustyurt Plateau. It was the center of the (indigenous) Khwarezmian civilization and a series of kingdoms, whose capitals were (among others) Kath, Gurganj (the modern Köneürgenç) and, from the 16th century on, Khiva. Today Khwarezm belongs partly to Uzbekistan and partly to Turkmenistan.
Khwarezm has been known also as Chorasmia, Khwarezmia, Khwarizm, Khwarazm, Khorezm, Khoresm, Khorasam, Harezm, Horezm, and Chorezm.
In Avestan the name is Xvairizem, in Old Persian Huwarazmish, in Modern Persian Khwārazm, in Arabic خوارزم Khwārizm, in Chinese 花剌子模 Huālázǐmó, in Uzbek Xorazm, in Greek Χορασμία and Χορασίμα, by Herodotus.
The Arab geographer Yaqut al-Hamawi in his Muʿǧam al-buldan wrote that the name was a compound (in Persian) of khwar (خوار), and razm (رزم), referring to the abundance of cooked fish as a main diet of the peoples of this area.