I can find no Welsh equivalent for the name "Claire'.
Bright, light
it means sundown.
It means Chist or Izvesten.
Sinclaire is a male name that means St. Claire.
Clear / bright. English version is Claire
"Claire" is typically a girl's name.
I suppose you mean "Marie-Claire", the first name and magazine name.
Claire Laing's birth name is Claire Heggie.
Claire Janaro's birth name is Claire Elaine.
Claire King's birth name is Claire Seed.
Claire Keim's birth name is Claire Lefebvre.