A noun in the 1960s versions of the Markirya glossed “darkness” (MC/222), perhaps derived from a root √DU as suggested by David Salo in a post to the Elfling mailing list in 2012 (Elfling/362.96).
Neo-Quenya: I’d generally use Q. huinë for “darkness” in Neo-Quenya, but that word is more for total darkness, whereas lúmë might be a less severe form of darkness, a variant of Q. lómë “night, dusk”.
lúmë (2) noun "darkness" (one wonders if Tolkien confused lúmë "time, hour" and lómë "night") (Markirya)