lanta (1) noun "a fall" (DAT/DANT (TALÁT) ), also lantë.
Quenya
lanta-
verb. to fall, to fall; [ᴱQ.] to drop
lanta-
fall
lanta
fall
lantar
fall
-r plural ending used on verbs with a plural subject (VT49:48, 50, 51), e.g. lantar "fall" in Namárië (with the plural subject lassi "leaves"), or unduláver as the pl. form of undulávë "licked down, covered" (PE17:72). The ending is sometimes missing where we might expect it; for instance, the verb tarnë "stood" has multiple subjects and yet does not appear as *tarner in PE17:71.
lanta-mindon
fallen-towers
lanta-mindon Qenya pl. noun "fallen-towers"; inflected compound lanta-ránar "in falling-moon" (with pre-classical locative -r) (MC:214; these forms are "Qenya")
lantë
noun. fall
The word lasselanta “leaf-fall, autumn” (LotR/1107) indicate the form this word should be lanta, which is how it appears in The Etymologies. However, the alternate lassewinta (PM/376) seems to be formed with the infinitive of the verb winta- rather than a noun, so perhaps lasselanta is a similar formation from the verb lanta- “to fall”.
The form lantë, appearing in Noldolantë “Fall of the Noldor” (S/87), more strongly resembles other Quenya nouns, which more often end in -e rather than -a. The noun atalantë “collapse, downfall” is a similar formation from the related verb [ᴹQ.] atalta-, though it could also be the past formation “downfallen” of this TALAT-stem verb.
lantë
fall
#lantë (1) noun "fall" in Noldolantë, q.v. Also lanta.
isilmë lantalassë
in the moon falling
The ninteenth line of the Markirya poem (MC/222). The first word is isilmë “moonlight” followed by the active-participle (“-ing”) of the verb lanta- “to fall” with the locative suffix -ssë (“in”), which modifies the entire phrase, as suggested by Helge Fauskanger (AL/Markirya).
Decomposition: Broken into its constituent elements, this phrase would be:
> isilmë lanta-la-ssë = “✱moonlight fall-ing-in”
lanta- (2) "fall" (DAT/DANT (TALÁT), Narqelion, VT45:26, VT49:54); lantar aorist tense pl. (Nam, RGEO:66); pl. pa.t. lantaner "fell" (pl.) (SD:246); lantier "they fell", a plural past tense of lanta- "fall" occurring in LR:47; read probably lantaner in LotR-style Quenya, as in SD:246. Also sg. lantië "fell" (LR:56); read likewise *lantanë? (The forms in -ier, -ië seem to be properly perfects.) Future tense lantuva, VT49:47. Participle lantala "falling" (with locative ending: lantalassë) in Markirya.