Sealt-wille
Bosworth & Toller Anglo-Saxon Old English Dictionary - sealt-wille
According to the Old English Dictionary:
-welle, an;
- sealt-wille
- f. A salt spring or well; hence Saltwell :-- In saltwyllan ; of saltwyllan, Cod. Dip. Kmbl. ia saliua (translator seems to have read salina), Mt. Kmbl. P.1. 5. sealt-wille