Galadriel

Tolkien himself translated 'Galadriel' as "glittering garland," "Maiden crowned with gleaming hair," and "maiden crowned with a radiant garland". Others have suggested that Galadriel consists of 'galad' ("light, radiance") + 'rî' ("crown") + 'iell' ("daughter"). Tolkien himself stated that the element 'galad' had no relation to Sindarin 'galadh' ("tree", or Silvan 'galad' "tree"), but people outside Lórien often made that mistake and called her 'Galadhriel' ("tree-garland") instead.
http://tolkiengateway.net/wiki/Galadriel#Etymology

The only difference between "radiant" and "light" in this case is that radiance is an adjective whereas, in this context, light is used as a noun. Galad means "light" or "radiance" A-N-C-E. Although the concepts are the same, it would be improper grammar to say "Galad"riel means "maiden crowned with a radiant garland". Maybe it means "maiden crowned with a garland of light/radiance", or something similar?

Galadriel is a beautiful name that suggests inner strength yet elegance. But Galadriel does not under any circumstance mean "Maiden crowned with a radiant garland". I know something of Tolkien's Elvish and the Elven word "galad" does not mean radiant, or gold, it means "light". I'm not sure about the suffix "riel", bu it does not mean "garlanded maiden", because in Elvish names, the suffix "wen" means "maiden". If anything, it would be my guess that Galadriel means "Lady of Light" or "Queen of Light", for in Tolkien's books Galadriel was the Queen of Lothlorien, and was often referred to as the Lady of Light.

The word galad means "radiant" in Sindarin from gal or kal meaning "shine." The word riel means "garlanded maiden" from the root rig meaning "twine, wreathe."

Actually, 'riel' does mean 'garlanded maiden' in Sindarin. 'iel' is a feminine suffix, and the 'r' comes from the verb 'rig', meaning to wreathe. And yes, 'galad' can mean 'radience' or 'light' - the concepts aren't that dissimilar. In fact, 'galad' comes from the Sindarin 'kal' meaning 'to shine'. And I'm getting this from a documented source, so I'm not making this up.

"Galad" also means "gold".

"Galad" does not mean "gold" — that is "laurel." "Galad" means "light."