Oʼdu (Ơ Đu), or Iduh, is a Mon–Khmer language of Vietnam and Laos. Once spoken by about 300 people in Tương Dương district, Nghệ An province, Vietnam (Đặng, et al. 2010), it is now considered to be almost extinct.
References
Đặng Nghiêm Vạn, Chu Thái Sơn, Lưu Hùng. 2010. Ethnic Minorities in Vietnam. Hà Nội: Thế Giới Publishers.