What is "duwa"

Duwa (died 1307), also known as Du'a, was khan of the Chagatai Khanate (1282–1307). He was the second son of Baraq. He was the longest reigning monarch of the Chagatayid Khanate and accepted the nominal supremacy of the Yuan dynasty as Great Khan before his death. Under his rule, the Chagatai Khanate reached its peak.