Its source is a Welsh expression meaning "Great queen, witch or goddess."
This girl's name is used in Welsh.
This is a very ancient name, and the meaning given is uncertain. The title Rigantona (meaning ''great queen'') was borne by a Celtic goddess of fertility, and authorities believe that title evolved into the name Rhiannon.
The 1975 song Rhiannon, written by Stevie Nicks and recorded by the band Fleetwood Mac, certainly brought this name to the attention of Western pop culture.