lumbulë noun "(heavy) shadow" (Nam, RGEO:67, PE17:168)
Quenya
lumbulë
noun. dark shadow, heavy shadow; deep in shadow
lumbulë
(heavy) shadow
Lumbar
lumbar
Lumbar name of a star (or planet), tentatively identified with Saturn (MR:435), evidently connected to lumbo, lumbulë (Silm)
undulav-
lick down
undulav- vb., literally "lick down" = cover (glossed "swallow" in PE17:72). Lumbulë undulávë ilyë tier "(heavy) shadow down-licked all paths", lyrical translation "all paths are drowned deep in shadow" (Nam). The pl. past tense would be unduláver (PE17:72).
A noun used in the Namárië poem and loosely translated as “deep in shadow” (LotR/377), but more accurately “heavy shadow, dark shadow” (PE17/72, 168; RGEO/59). It is a derivative of the root √LUB “shadow” (PE17/168), perhaps an elaboration of ᴹQ. lumbe “gloom, shadow” from The Etymologies of the 1930s (Ety/LUM).
Neo-Quenya: Based on its use, I suspect lumbulë refers to a great expanse of shadow (“shadowness”) rather than an individual cast shadow, which is Q. hala.