Legolas Greenleaf was a member of the House of the Tree and was one of Galdor's scouts. He escaped the Fall of Gondolin with its survivors and led them across the Cristhorn. After the First Age he moved to Tol Eressëa where he remained ever after, going by the name Laiqalassë.
The Legolas of Gondolin, whom Tolkien would have likely renamed, has a different etymology. His name Laiqalassë is the Quenyan rendering of the name, from the primitive Quenya words laica ("green") and lassë ("leaf"). The Sindarin Legolas translates to "Green-leaf" and also "Keen-sight" from leg ("keen, piercing") and last ("look, glance").
Other versions of the legendarium
- The History of Middle-earth, Vol. 2: The Book of Lost Tales Part Two, III: "The Fall of Gondolin"
- The History of Middle-earth, Vol. 1: The Book of Lost Tales Part One, Appendix: Names in the Lost Tales – Part I
- The History of Middle-earth, Vol. 5: The Lost Road and Other Writings, Part Three: "The Etymologies"