A word for “sky” in an early name list from the 1910s and appearing in a couple early names: G. Thlim Quing Ilon “✱Folk of the Heavenly Arc” and G. Cris o Teld Quing Ilon “Gully of the Rainbow Roof” (PE13/101, 104), the latter revised to G. Cris Ilbranteloth (LT2/202). In the contemporaneous Gnomish Lexicon, however, G. Ilon was the name of Ilúvatar (GL/50).
Gnomish
telu
noun. end
telu-
verb. to close, end, finish
telumaithor
masculine name. Swordsman of the Sky
telum
noun. roof; sky
telm
noun. roof; sky
teld
noun. roof
clum(mi)
noun. mushroom
dai
noun. sky
dâ
adjective. high
ilon
noun. sky
luithon
noun. sky
A word for “sky” in the Gnomish Lexicon of the 1910s, an elaboration of G. lui “blueness” (GL/55).
teltha-
verb. cover in
telthon
noun. roof
ufra
adjective. outer
A noun appearing as {clumbi >>} G. clummi or clum “mushroom” in the Gnomish Lexicon of the 1910s (GL/26), cognate to ᴱQ. telumbe “mushroom” under the root ᴱ√TELE “cover in” in the contemporaneous Qenya Lexicon (QL/90). It is an example of the sound change whereby tl became cl in Gnomish.
Neo-Sindarin: This sound change occurred in Noldorin of the 1930s but not Sindarin of the 1950s and 60s; compare N. eglenn to S. edlen(n) “exiled” (Ety/LED; PE17/51). To avoid these questions, I would adapt this Gnomish word as ᴺS. telum “mushroom” for purposes of Neo-Sindarin.