In localised Celtic polytheism practised in Britain, Sulis was a deity worshipped at the thermal spring of Bath (now in Somerset). She was worshipped by the Romano-British as Sulis Minerva, whose votive objects and inscribed lead tablets suggest that she was conceived of both as a nourishing, life-giving mother goddess, and as an effective agent of curses wished by her votaries.
The exact meaning of the name Sulis is still a matter of debate among linguists, but one possibility is "Eye/Vision", cognate with Old Irish súil "eye, gap", perhaps derived from a Proto-Celtic word *sūli- which may be related to various Indo-European words for "sun" (cf. Homeric Greek ηέλιος, Sanskrit sūryah "sun", from Proto-Indo-European *suh2lio-).
Sulis was the local goddess of the thermal springs that still feed the spa baths at Bath, which the Romans called Aquae Sulis ("the waters of Sulis"). Her name primarily appears on inscriptions discovered at Bath, with only a single instance outside of Britain at Alzey, Germany. This is not surprising, as Celtic deities often preserved their archaic localisation. They remained to the end associated with a specific place, often a cleft in the earth, a spring, pool or well. The Greeks referred to the similarly local pre-Hellenic deities in the local epithets that they assigned, associated with the cult of their Olympian pantheon at certain places (Zeus Molossos only at Dodona, for example). The Romans tended to lose sight of these specific locations, except in a few Etruscan cult inheritances and ideas like the genius loci, the guardian spirit of a place.