Two entries with the name Dôn.
Dôn
Dôn is the Mother goddess, daughter of Mathonwy, sister of Math fab Mathonwy and wife of Beli.
She is the Welsh equivalent of the Irish Danu. Traditionally she was the mother of Gilfaethwy, Arianhrod and Gwydion fab Dôn, as well as several others, as illustrated in her traditional genealogy. It has been suggested that Dôn was the original of Do, even though this would mean a change of gender.
Dôn
Father of Arthur’s warriors Amathaon and Gofannon. He has several sons in non-Arthurian Welsh legend. He is originally an Irish god.
Source
Culhwch and Olwen | Late 11th century