Tuyuhun (Chinese: 吐谷渾), also known as ‘Azha from Tibetan script, is an extinct language once spoken by the Tuyuhun of northern China about 500 AD. The existence of the Tuyuhun, and consequently their language, is first attested in the Book of Song, compiled around 488 AD.
Alexander Vovin (2015) identifies the extinct Tuyuhun language as a Para-Mongolic language, meaning that Tuyuhun is related to the Mongolic languages as a sister clade but is not directly descended from the Proto-Mongolic language. The Khitan language is also a Para-Mongolic language. Tuyuhun had previously been identified by Paul Pelliot (1921) as a Mongolic language.
Shimunek (2017) reconstructs some Tuyuhun words as:
Vovin (2015) also reconstructs several words using Early Middle Chinese readings of transcribed Tuyuhun lexical items.