From ᠬᠥᠬᠡ (köke, “blue”) + ᠨᠠᠭᠤᠷ (naɣur, “lake”).
ᠬᠥᠬᠡᠨᠠᠭᠤᠷ • (köke naɣur) (Cyrillic spelling Хөх нуур)