A name the Sindar used for themselves, mostly used in the plural forms Eglath, Eglain or Egladhrim (S/58, MR/170, WJ/365). It was often applied more specifically to the people of Círdan (WJ/380, PM/392 note #35). This name is derived from the adjective eglan “forsaken” < ✶heklanā, whereas the prefixal form Egla- (surviving only in names) was derived from the primitive noun form ✶hek(e)lā “a waif or outcast” (WJ/365). Tolkien experimented with a large variety of similar forms in Notes on Names from 1957, including eglon (PE17/140-142); see that entry for details.
Conceptual Development: In the Gnomish Lexicon from the 1910s, the word G. Egla was given as the Gnomish name for all Elves, meaning “a being from outside” and related to the word G. edh “outside” (which took the form eg before l) and ᴱQ. Elda (GL/32; LT1A/Eldar, Eglamar). Its class-plural Eglath also appeared in the Gnomish Lexicon (GL/50, entry idhrin). When Tolkien revised the phonology of the Noldorin language, he switched the language of this word to Ilk. Egla “Elf”, equivalent of ᴹQ. Elda and N. Eledh (Ety/ELED).
After Tolkien abandoned the Ilkorin language, he revised the meaning of this name to “The Forsaken”, a name the Sindar gave themselves after they were left in Beleriand (S/58). In this new sense, the class-plural S. Eglath “Forsaken” first appeared in a chart of the divisions of the Elves from the early 1950s, where it was equated to (and possibly replaced) Q. Ecelli of the same meaning (MR/170). The singular form Eglan appeared in his Quendi and Eldar essay from 1959-60, equated to Q. Hekel and with the etymology discussed above (WJ/365).
A name for region of Beleriand where the people of Círdan dwelled (WJ/379). This name is effectively a combination of the prefixal form Egla- of Eglan “Forsaken (Elf)” and bâr “home”, derived from ancient ✶(h)ekla-mbar (WJ/365).
Conceptual Development: In the Gnomish Lexicon from the 1910s, the name G. Eglamar “Elfinesse, Elfhome” appeared (among other variations) as the Gnomish equivalent of ᴱQ. Eldamar, home of the Elves in Valinor (GL/32). This name also appeared with this meaning in drafts of the Lays of Beleriand from the 1920s (LB/157, 181). A number of variations of this name appeared in early name lists, including G. Eglavain (LTI2/320) and ᴱN. Uidhelian (PE13/155) >> Idhelian (PE15/61), but these variations did not appear in later writings.
After Tolkien revised the phonology of the Noldorin language in The Etymologies from the 1930s, this name became Ilk. Eglamar “Elvenhome” containing the Ilkorin word for “Elf”: Ilk. Egla (Ety/ELED). However, the name did not appear in the narratives of that period. After Tolkien abandoned the Ilkorin language, the name reappeared in his Quendi and Eldar essay from 1959-60, with the revised meaning given above (WJ/379).