Also found in: Wikipedia.
a river in the Yakut ASSR, a left tributary of the Viliui. The Ygyatta is 601 km long and drains an area of 11,200 sq km. It rises on the Viliui Plateau and cuts through traprock to form shivery (rocky sections with fast-flowing water). The lower course lies in the Central Yakut Lowland. The river is fed by rain and snow and has a mean flow rate of approximately 30 cu m per sec. The Ygyatta freezes over in October, and the ice breaks up in May.