Khwārezmian is an extinct East Iranian language closely related to Sogdian. The language was spoken in the area of Khwarezm, centered in the lower Amu Darya south of the Aral Sea. Knowledge of Khwarezmian is limited to its Middle Iranian stage and, as with Sogdian, little is known of its ancient form. From the writings of the great Khwarezmian scholars, Al-Biruni and Zamakhshari, we know that the language was in use at least until the 13th century, when it was gradually replaced by Persian for the most part, as well as several dialects of Turkic. Other than the astronomical terms used by al-Biruni, our other sources of Khwarezmian include Zamakhshari's Arabic–Persian–Khwarezmian dictionary and several legal texts that use Khwarezmian terms and quotations to explain certain legal concepts, most notably the Qunyat al-Munya of Jalal ad-Din al-'Imadi. The noted scholar W.B. Henning was preparing a dictionary of Khwarezmian when he died, leaving it unfinished. A fragment of this dictionary was published posthumously by D.N. MacKenzie in 1971.
Before the advance of Islam in Transoxiana, Khwarezmian was written in a script close to that of Sogdian and Pahlavi with its roots in the imperial Aramaic script. From the few surviving examples of this script on coins and artifacts, it has been observed that written Khwarezmian included Aramaic logograms or ideograms, that is Aramaic words written to represent native spoken ones e.g. ??? for سرذ, sarδ, "year", ???? for خداك, xudāk, "self" and ???? for اى شاه, ī šah, "the king". After the advance of Islam, Khwarezmian was written using an adapted version of the Perso-Arabic alphabet with a few extra signs to reflect specific Khwarezmian sounds, such as the letter څ which represents /ts/ and /dz/, as in the traditional Pashto orthography.
Khwarezmian script was added to the Unicode Standard in March, 2020 with the release of version 13.0. The Unicode block for Khwarezmian, called Chorasmian, is U+10FB0–U+10FDF:
