The Sindarin form of Q. Elwë, the original name of Thingol (S/56). This Sindarin name is derived from the Quenya, because in Sindarin short final vowels vanished and then final [w] usually became [u]: Elwe > Elw > Elu (PE17/189). This Sindarin name appeared as an element in the names of many of his descendants.

Conceptual Development: In the earliest Lost Tales, the leader of the third tribe of Elves was named Sol. Ellu (LT1/155), though at this early stage the character was distinct from the contemporanerous character that would develop into Thingol (G. Tinwelint). The name changed to (Telerin?) Elu with one l in very early Silmarillion drafts (SM/13, 85), and was given the Qenya cognate of ᴱQ. Elwe.

In the Annals of Beleriand from the 1930s, ᴹQ. Elwe was identified as the brother of Thingol (SM/264) and so remained in Silmarillion drafts of that period (LR/217). In The Etymologies, Tolkien specifically indicated that the Noldorin form of his name Elw (= Elu) was not used (Ety/WEG), probably because in this conception Elwe remained in Valinor. It was not until Silmarillion revisions from the 1950s-60s that the name Elwe was assigned to Thingol, at which point his brother was renamed to Q. Olwë (MR/82). At this stage, the Sindarin form of his name Elu was also introduced (MR/86).