What is "adsullata"

In Celtic mythology, Adsullata was a river goddess of the Continental Celts associated with the River Savus (Sava) in Noricum. This deity is known from a single inscription found at Saudörfel, Austria.

Later she came to Brittany from Celtic Gaul and was believed to be a goddess of hot springs and the origin of the Anglo-Celtic sun goddess, Sul.