(small bird) 1) aew. No distinct pl. form. 2) fileg, pl. filig; the form filigod appears as an alternative singular. or
Noldorin
filigod
noun. small bird
filigod
noun. small bird
fileg
noun. small bird, small bird, [G.] *sparrow
aew
noun. (small) bird
emelin
noun. yellow bird, "yellow hammer"
emlin
noun. yellow bird, "yellow hammer"
emmelin
noun. yellow bird, "yellow hammer"
fileg
noun. small bird
A noun in The Etymologies of the 1930s glossed “small bird” derived from the root ᴹ√PHILIK and cognate to ᴹQ. filit (filik-) of the same meaning (Ety/PHILIK). Tolkien said fileg was an “analogical singular” form (along with another singular form filigod) based on its plural form filig. That is because the final -k in ✱philik was lost in ancient times, as explained in Common Eldarin: Noun Structure from the early 1950s (PE21/72) so that its historical phonetic development would have produced singular N./S. ✱fil. This form was deemed unsuitable, and a new singular form fileg was constructed based on the plural. Something similar happened with S. thoron “eagle”.
Conceptual Development: The Gnomish Lexicon of the 1910s had G. bilin or bilinc for “a small bird, especially sparrow”, a diminutive form of G. bil “bird” (GL/22, 23).
Neo-Sindarin: I think it is likely that fileg can also be used to refer to sparrows for purposes of Neo-Sindarin, since its Quenya cognate filit was in one place glossed “sparrow, small bird” (PE21/56).