{ð} n. 'looking-cristal', looking-glass. >> Nen Cenedril
Sindarin
heledh
noun. glass
heledh
noun. glass
heledh
'looking-cristal'
heledh
glass
heledh (i cheledh, o cheledh), pl. helidh (i chelidh) if there is a pl.
heledh
glass
(i cheledh, o cheledh), pl. helidh (i chelidh) if there is a pl.
heledhren
adjective. glassy, like glass, of glass
cenedril
'looking-cristal'
n. 'looking-cristal', looking-glass. >> Nen Cenedril
The basic Sindarin word for “glass”, a loan word from Khuzdul kheled (PE17/37; RS/466). The Eldar of Valinor invented glass independently, so the Quenya “glass” words were distinct.
Conceptual Development: The Gnomish Lexicon of the 1910s had G. celc “glass” along with (archaic) variants G. celeg and caileg, all derived from the early root ᴱ√kail(i)k (GL/25). These apparently replaced rejected forms {talp}, {calp}, and {telc} of the same meaning (GL/69). The “glass” word became ᴱN. celch or caileg “glass” in Early Noldorin Word-lists of the 1920s (PE13/140).
In The Etymologies of the 1930s the “glass” word became N. hele derived from the root ᴹ√KHYEL(ES) “glass” like its Quenya cognate ᴹQ. hyelle (Ety/KHYEL(ES)). In the 1930s Noldorin and Quenya were direct contact for most of their history, but this was no longer the case for Sindarin and Quenya of the 1950s and 60s. As a result, Tolkien decided that glass was an independent invention in both Valinor and Middle Earth, so that the Quenya and Sindarin words were no longer related as described above.