A word for “gloom” and “unrelieved darkness” such as a night without stars or moon (VT41/8), with an archaic form †fuinë [ɸuine] (PE19/71). In one place Tolkien said it is was used of darkness as an ethereal substance, the opposite of Q. linquë which was ethereal light (NM/279, 283). While light as a substance is an idea somewhat supported by reality (e.g. photons), darkness as a substance is necessarily poetic or mythic.
Conceptual Development: The earliest iteration of this word was ᴱQ. hui or fui “fog, dark, murk, night” from the early root ᴱ√ǶUẎU (QL/41), also appearing with the gloss “dark, murk” in the Poetic and Mythological Words of Eldarissa (PME/41). It was equated to ᴱQ. Fui, the name of the Death-goddess Nienna (QL/40). In the Oilima Markirya from around 1930, the word hui was given the translation “evening” in the phrase hui oilima man kiluva “Who shall see the last evening?” (MC/214).
In The Etymologies of the 1930s it was ᴹQ. fuine, huine “deep shadow” under the root ᴹ√PHUY (Ety/PHUY), and in various iterations of the ᴹQ. Lament of Atalante of the 1930s and 40s, huine was glossed “shadow” (LR/47, 56; SD/246, 310). In the Outline of Phonetic Development (OP1) of the 1930s, it was glossed “deep shadow, nightshade”, with fuine being its normal form but huine being its form in the {Lindarin >>} Vanyarin dialect (PE19/31). However in the Outline of Phonetic Development (OP2) of the 1950s, Tolkien revised this so that huine was its normal Quenya form in all dialects, fuine being archaic and pronounced with a pure labial “f” [ɸ] rather than the later labio-dental “f” [f] (PE19/71).
In writings after this point, it usually as huine (VT41/8; SA/fuin), but in some notes from the late 1960s Tolkien considered making huine the Vanyarin form again, with fuine being the form in Noldorin Quenya (NM/279).
Neo-Quenya: I prefer the notion that [[q|[ɸu] became [hu]]] in all Quenya dialects before [[q|[ɸ] became [f]]], so I would use the form huine. I would use it with the sense “darkness, deep shadow” for a particularly lightless darkness, but only metaphorically or poetically for darkness as ethereal substance in and of itself, as I believe the Elves would have been well aware that darkness was actually the absense of light.
huinë noun "deep shadow" (PHUY), "gloom" (VT41:8), "gloom, darkness" (SA:fuin), also used for "shadow" = Sauron (LR:56). Possessive (adjectival) form huinéva in the name Taurë Huinéva, q.v. In earlier sources, huinë is quoted as a variant of fuinë, but according to VT41:8, huinë is the proper Quenya form and fuinë is Telerin.With prefix nu- "under" and allative ending -nna in nuhuinenna (SD:246); also unuhuinë "under-shadow" (LR:47).