Deori is a Tibeto-Burman language spoken by the Deori people of Assam

Assam

Assam , also, rarely, Assam Valley and formerly the Assam Province , is a northeastern state of India and is one of the most culturally and geographically distinct regions of the country...

. It is one of the official languages of Arunachal Pradesh

Arunachal Pradesh

Arunachal Pradesh is a state of India, located in the far northeast. It borders the states of Assam and Nagaland to the south, and shares international borders with Burma in the east, Bhutan in the west, and the People's Republic of China in the north. The majority of the territory is claimed by...

. Only one of the Deori tribes, the Dibongya, has retained the language, the others having shifted to Assamese

Assamese language

Assamese is the easternmost Indo-Aryan language. It is used mainly in the state of Assam in North-East India. It is also the official language of Assam. It is also spoken in parts of Arunachal Pradesh and other northeast Indian states. Nagamese, an Assamese-based Creole language is widely used in...

, but among the Dibongya it is vigorous.

The Deori and their language are frequently called Sutiya. However, that name is not specific to the Deori; Deoni name means temple guard, and they are the traditional priests of the Chutiya region.