1) celeg (agile), lenited geleg, pl. celig, 2) lagor, analogical pl. legyr, 3) legrin (rapid), no distinct pl. form, 4) lint (no distinct pl. form)
Sindarin
celeg
adjective. *hasty, hasty; [N.] agile, swift; [ᴱN.] lambent
celeg
adjective. swift, agile, hasty
celeg
celeg
celeg
swift
celeg
agile
celeg (swift), lenited geleg, pl. celig
celeg
swift
(agile), lenited geleg, pl. celig
celeg
agile
(swift), lenited geleg, pl. celig
heledh
noun. glass
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.
heledh
noun. glass
lagor
adjective. swift, rapid
The form lhegin in the published Etymologies might be a misreading for lhegrin, see VT/45:25. As noted by Bertrand Bellet, the two forms are listed side by side, and they may simply be doublets, but it is also possible that we have here a singular followed by its plural.
lim
adjective. swift
adj. swift. Noro lim, noro lim Asfaloth. 'Run swift, run swift Asfaloth'. Q. limbe,#linta.
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.
lagor
swift
analogical pl. legyr
legrin
swift
(rapid), no distinct pl. form
lint
swift
(no distinct pl. form)
Probably OS keleka, from PQ kyelekâ, Root KYELEK