A word appearing in Definitive Linguistic Notes (DLN) from 1959 glossed “innumerable” as a combination of pen “without” and the gerund of noedia- “to count”. The oe [œ] is archaic and the modern form would be pennediad.
Sindarin
arnoediad Archaic
adjective. unnumbered, without reckoning
arnœdiad
adjective. innumerable, countless, endless, without reckoning, numberless
arnediad
adjective. unnumbered, unnumbered, [N.] without reckoning, numberless, innumerable, countless, endless
pennoediad
adjective. innumerable
nirnaeth arnoediad
proper name. Tears Unnumbered
The tragic battle in which the forces of Morgoth defeated the Elves and Men of Beleriand, translated “Tears Unnumbered” (S/192) or “Unnumbered Tears” (WJ/165). This name is a combination of nirnaeth “lamentation” and the archaic form †arnoediad “unnumbered” (Ety/NOT).
Conceptual Development: Although translated “Unnumbered Tears” throughout Tolkien’s writing, the Elvish form of the name changed greatly over the years. In the earliest Lost Tales, this name first appeared as G. Nínin-Udathriol (LT2/84). In the Lays of Beleriand from the 1920s, the name was revised to ᴱN. Nínin Unothradin or Nirnaithos Unothradin (LB/21), then revised again to ᴱN. Nirnaith Únoth >> Nirnaith Ornoth (LB/79).
In the earliest Silmarillion drafts from the 1930s the name was changed to N. Nirnaith Irnoth >> Nirnaith Dirnoth (SM/312, LR/136), then again to N. Nirnaith Arnediad (LR/147), the last of these also appearing as a late revision in the Lays of Beleriand (LB/102). The form Nírnaeth Arnediad with a long í appeared in The Etymologies (Ety/NAY), along with the archaic form of its second element arnœdiad (Ety/NOT). In the Silmarillion revisions from the 1950s-60s Tolkien switched to this archaic form in the main narratives (WJ/165), using S. Nirnaeth for earlier N. Nirnaith after his [[n|revision of [ai] to [ae]]].
Nírnaeth Arnoediad
noun. unnumbered tears
nírnaeth (“lamentation”) < nîr (“tear”) + naeth (“woe”), ar- (pref. “without”) + noediad (ger. of noedia-, nedia- “count”)
arnediad
unnumbered
arnediad (without reckoning, numberless), pl. ?arnediaid. Since the word literally means ”without reckoning” (ar + nediad) it is unclear whether it would pluralize as a common adjective. Alternative form arneidiad (VT46:6).
arnediad
unnumbered
(without reckoning, numberless), pl. ?arnediaid. Since the word literally means ”without reckoning” (ar + nediad) it is unclear whether it would pluralize as a common adjective. – Alternative form arneidiad (VT46:6).
aronoded
innumerable
aronoded (countless, endless), pl. erenedid (archaic erönödid)
aronoded
innumerable
(countless, endless), pl. erenedid (archaic erönödid)
Nírnaeth Arnoediad
Nirnaeth Arnoediad
pen-noediad
adjective. innumerable
adj. innumerable.
A Sindarin word for “unnumbered” appearing in its archaic form arnoediad [arnœdiad] in the name Nirnaeth Arnoediad “[Battle of] Tears Unnumbered” and in its modern form in the variant name Dagor Arnediad (WJ/28). The e vs. archaic œ is the result of the Sindarin sound change of [[s|[œ] to [e]]] occurring sometime in the First Age. This word is a combination of ar- “without” and the gerund of the verb nedia- “to count”, so more literally “✱without count” or “countless”.
Conceptual Development: The modern and archaic forms N. arnediad and N. arnœdiad appeared in The Etymologies of the 1930s with the translations: “without reckoning, numberless” (Ety/AR²) and “innumerable, countless, endless” (Ety/NOT). This was also the form used in the narratives of the 1930s and later. Prior to this point, Tolkien used numerous earlier forms:
The Gnomish Lexicon of the 1910s had G. udathnarol and udathriol “countless” as a combination of negative prefix G. u- and adjective forms of the verb G. tath- “count” (GL/74), with udathriol also appearing in the contemporaneous Lost Tales (LT2/84). Udathriol also appeared briefly in the Lays of Beleriand (LB/21 note #13), but underwent a number of changes in that narrative (see below).
Early Noldorin Word-lists of the 1920s had ᴱN. inathui and {inathadwed >} inathadren “innumerable” as a combination of negative prefix ᴱN. i- and an adjectival form ᴱN. nath “number” (PE13/148). A similar form unothradin appeared in the Lays of Beleriand (LB/6).
These Early Noldorin Word-lists also had ᴱN. ornoth “numberless” as a combination of ᴱN. or- “without” and ᴱN. noth “number”, with variants únoth “without number, countless” and onath “numberless” (PE13/151, 155). Ornoth and únoth also appeared in the Lays of Beleriand (LB/59, 79).
The Lays of Beleriand also had Nirnaith Dirnoth “Unnumbered Tears” (LR/136), a form that reappeared in Silmarillion narratives from around 1930 as {Nirnaith Irnoth >>} Nirnaith Dirnoth before being revised to Nirnaith Arnediad (SM/312).
Tolkien used arnediad or arnoediad thereafter.