A tree in Tirion made after Telperion and translated “White Tree” (S/59). It may be a combination of galadh “tree” and the root THIL “shine silver” (SA/sil). The final element seems to be the patronymic suffix -ion, the last of these perhaps indicating its decent from Telperion.
Conceptual Development: In Silmarillion drafts from the 1930s, N. Galathilion was another name for Telperion (LR/209). In The Etymologies it was glossed the “White Tree of Valinor” and had the derivation given above (Ety/BAL, GALAD, THIL), though the final element -ion was not explained. In Lord of the Rings drafts from the 1940s, it was glossed “Silver Cherry”, but as Christopher Tolkien pointed out, this was not its actual meaning (RS/187).