adj. thick, of single thing. Tolkien seems to consider that it is not a suitable Sindarin form.
Primitive elvish
del
root. thick, dense
ndel
root. thick, dense
Sindarin
delw
adjective. thick
le
thick
2 adj. thick, of single thing. Tolkien seems to consider that it is not a suitable Sindarin form.
tûg
thick
tûg (lenited dûg, pl. tuig)
tûg
thick
(lenited dûg, pl. tuig)
Noldorin
tûg
adjective. thick, fat
Quenya
tiuca
thick, fat
tiuca adj.("k") "thick, fat" (TIW)
Beware, older languages below! The languages below were invented during Tolkien's earlier period and should be used with caution. Remember to never, ever mix words from different languages!
Early Primitive Elvish
tiw̯i
root. thick
Early Quenya
tunga
adjective. thick, dense
tyúka
adjective. thick
A rejected root meaning “thick, dense” that appeared in rough etymological notes for the name of S. Glorfindel < glaur-phin-dela = “gold-hair-thick” (PE17/17). One of the proposed Quenya forms was nelya beside lelya, indicating Tolkien was considering strengthening the root form to √NDEL.
Neo-Eldarin: For purposes of Neo-Eldarin, I think it would be worth salvaging this root in this strengthened form ᴺ√NDEL “thick, dense”, since I know of no other good options for words meaning “dense”.