Belisama

In Celtic polytheism, Belisama (epigraphically Bηλησαμα) was a goddess worshipped in Gaul. She is identified with Minerva in the interpretatio romana.

Etymology
the etymology of her name has been taken to translate to "brigh one", i.e. containing a superlative suffix -isama attached to the root bel "bright"; based on this she has also been speculatively claimed as companion of Belenus, whose name seems to contain the same root. But the root bel has also (for either deity) been interpreted differently, e.g. as bel "strong".

A Gaulish inscription found at Vaison-la-Romaine in Provence (RIG G-172) shows that a nemeton was dedicated to her:
 * СΕΓΟΜΑΡΟС/ ΟΥΙΛΛΟΝΕΟС/ ΤΟΟΥΤΙΟΥС/ ΝΑΜΑΥСΑΤΙС/ ΕΙѠΡΟΥ ΒΗΛΗ/СΑΜΙ СΟСΙΝ/ ΝΕΜΗΤΟΝ
 * Segomaros Ouilloneos tooutious Namausatis eiōrou Bēlēsami sosin nemēton
 * "Segomarus Uilloneos, citizen [toutius] of Namausus, dedicated this sanctuary to Belesama"

the identification with Minerva in Gallo-Roman religion is established in a Latin inscription from Saint-Lizier (anciently Consoranni), Ariège department (CIL XIII, 8):
 * Minervae / Belisamae / sacrum / Q(uintus) Valerius / Montan[us] / [e]x v[oto?]

the French toponyms Beleymas and Bellême (found in the Dordogne and Orne departments, respectively) are based on the theonym.

the presence of the goddess in Britain is more difficult to establish. Based on Ptolemy listing a "Belisama estuary", River Ribble in England seems to have been known by the name Belisama in Roman times. However, it is also said to be the name of the River Mersey.