Father of Legolas (LotR/240) translated “vigorous spring”, a combination of tharan “vigorous” and the lenited form of tuil “spring” (PE17/27, 187).
Conceptual Development: In the drafts of the Lord of the Rings appendices, Tolkien indicated that this name was Lemberin (PM/36), so it is possible he considered making this name Nandorin like that of his son Legolas, but elsewhere he and his name were clearly marked as Sindarin (UT/256, PE17/27).
_prop.n. _vigorous spring. >> tharan, tharanduil