An archaic word for “second”, replaced in modern Quenya by attëa (VT42/25). The archaic word appeared as the ancient name of the tribe of the Noldor: Tatyar “Seconds” (WJ/380, 420). There was another variant atya appearing in a few archaic names like Atyarussa “Second-russa” (VT41/10) and (probably) Atyamar “✱Second Home” (NM/51).
Quenya
tatya
second
tatya Archaic
ordinal. second
atya
second
#atya (1) adj. "second" in Atyarussa "Second russa" (VT41:10)
atya
ordinal. second
tatya-
verb. to double
tatya- vb. "to double" (TATA)
attëa
second
attëa ordinal "second", replacing the archaic form tatya (VT42:25)
attëa
ordinal. second
The usual Quenya word for “second”, an adjectival form of atta “two” (VT42/25).
Conceptual Development: The word ᴱQ. potsina appeared in the Qenya Lexicon of the 1910s with the glosses “rearward, back, rear, hinder”, and based on ᴱQ. pote “after, behind (of place)” under the early root ᴱ√POT-I (QL/75). In the Early Qenya Grammar of the 1920s it had the added meaning “second” along with “next, following” (PE14/51, 82).
The Etymologies of the 1930s had ᴹQ. neuna “second” derived from ᴹ✶ndeu̯na under the root ᴹ√NDEW “follow, come behind” (Ety/NDEW). Neuna was thus semantically similar to ᴱQ. potsina where “second” = “✱following”. The word neuna has a variant nyûna that Tolkien marked with a “?” (EtyAC/NDEW).
Neo-Quenya: For purposes of Neo-Quenya, I would use attëa as the usual word for “second”, but I would retain neuna for “second” in the sense “✱immediately following, next”.
neuna
second
neuna adj. "second" (NDEW)
tatya archaic ordinal "second". Nominal pl. Tatyar "Seconds, Second Ones", the original name of the Noldor as the Second Clan of the Elves (or rather the direct Quenya descendant of the original name, which was probably Tatjāi). (WJ:380) Later, tatya as an ordinal was replaced by attëa (VT42:25).