noun: (historical) The Sassanian and post-Islamic Persian name for the region of Parthia located in north east of Persia (Iran), sometimes covering also parts of Central Asia and Afghanistan; the Greater Khorasan.
noun: A pre-2004 province of Iran which subsequently divided into the South Khorasan, North Khorasan, and Razavi Khorasan provinces.
noun: (proscribed) Ellipsis of Daesh-Khorasan (“IS/ISIL/ISIS affiliate”). [(politics) An Islamic terrorist group located in Pakistan and Afghanistan affiliated with Daesh (“IS, ISIL, ISIS”)]
