lumbo noun "cloud" (pl. lumbor in Markirya), also glossed "gloom; dark, shade" (PE17:72, 168). In early "Qenya", lumbo was glossed "dark lowering cloud" (LT1:259)
Quenya
lumbo
noun. cloud; gloom, dark, shade, cloud, [ᴱQ.] dark lowering cloud; [Q.] gloom, dark, shade
lumbo
cloud
Lumbar
lumbar
Lumbar name of a star (or planet), tentatively identified with Saturn (MR:435), evidently connected to lumbo, lumbulë (Silm)
fanya
(white) cloud
fanya noun "(white) cloud" (translated "sky" in FS); pl. fanyar in Namárië(Nam, RGEO:67). ). Used "only of white clouds, sunlit or moonlit, or clouds gilded or silvered at the edges by light behind them", not "of storm clouds or cloud canopies shutting out the light" (PE17:174). Cf. lumbo, q.v. According to VT46:15, fanya was originally given as an adjective "white" in the Etymologies; the printed version in LR wrongly implies that fanya and fána both mean "cloud", whereas actually the first was at this stage meant to be an adjective "white" whereas fána is both noun "cloud" and adj. "white". However, Namárië and later emendations to the entry SPAN in Etym indicate that Tolkien would later think of fanya as a noun "cloud", perhaps giving it the same double meaning as fána: noun "cloud" as well as adjective "white". According to PE17:26, fanya was originally an adjectival form "white and shining" that was however often used as a noun "applied to various things, notably to white clouds lit by sun or moon". In Namárië, the word is used poetically with reference to the hands of Varda (she lifted her hands ve fanyar "like clouds").
fána
cloud
fána (2) noun "cloud" _(SPAN, VT46:15). _Cf. fana.
ungo
cloud, dark shadow
ungo noun "cloud, dark shadow" (UÑG)
A word for “cloud” appearing in the plural form lumbor “clouds” in the Markirya poem of the 1960s. An identical form ᴱQ. lumbo appeared five decades earlier in the Qenya Lexicon of the 1910s with the gloss “dark lowering cloud” as a derivative of the early root ᴱ√LUVU (QL/57). The context of the 1960s Markirya poem was that of a gathering storm, so it seems likely lumbor also referred to dark or stormy clouds. As further support of this, in other late notes lumbo was glossed “gloom” (PE17/72) or “dark, shade” (PE17/168) as a derivative of √LUM or √LUB “shadow, darkness”.
Neo-Quenya: For purposes of Neo-Quenya, I would assume lumbo mainly means “dark cloud”, along with the general darkness and gloom of bad weather.