Rhiannon

The name 'Rhiannon' arises in the First and Third Branches of the Mabinogi legends. The legends called 'The Four Branches of the Mabinogi' had their origin in Ireland, and reached Wales as a manuscript batch in the last quarter of the twelfth century, where they were redacted and written in Medieval Welsh by a listening scribe.
'Rhiannon' is one of many examples of names in the legends which are phonetic renderings of Irish names of places or people, composed of two or more gaelic words and written as a single word in Middle Welsh - other examples being 'Arawn', 'Mabinogi', 'Annwfyn', 'Caer Sidi', etc.
'Rhiannon' is the fusion of the two gaelic words - ríoghan án - written phonetically in Middle Welsh as a single word. The gaelic word 'ríoghan' (Pr: ree/on) means 'fair lady' or 'noble lady'. The gaelic word 'án' (Pr: awn) means 'beautiful' or 'pleasant' or 'comely'. Whence 'Rhiannon' means "Beautiful noble lady'.

I remember hearing Rhiannon (Re-an-non) when I was a child. I looked on the net to find its meaning. It was the Welsh Goddess of Death according to whatever site I found 20 years ago.

A Welsh name originally meaning 'she who inspires' although it came to mean 'queen-like' or 'leader' as it was often given to the first daughter.

Rhiannon is also known in different mythologies as the Tripple Goddess. She is also known from the fame of The Birds of Rhiannon.