Quenya 

oialë

everlasting [?age]

oialë noun "everlasting [?age]" (Reading of gloss uncertain)(OY).Also adverb "eternally, in eternity" (PE17:59) or "forever" (PE17:69), so used in Namárië (Nam, RGEO:67)

oialë

noun/adverb. forever; everlastingly, eternally, in eternity, forever; everlastingly, eternally, in eternity; [ᴹQ.] everlasting age

Quenya [LotR/0377; PE17/059; PE17/069; PE17/073; PE17/074; PE17/169; RGEO/58; RGEO/59; RGEO/61] Group: Eldamo. Published by

oialëa

eternal

oialëa adj. "eternal" (PE17:59)

oialëa

adjective. eternal

ialë

everlasting age

[ialë noun "everlasting age" (GEY; the word "age" dropped out in the Etymologies as printed in LR; see VT45:14. Replaced by oialë.]

aira

eternal

[aira (4) adj. "eternal" (EY, VT45:13). Changed by Tolkien to oira.]

oira

eternal

oira adj. "eternal" (OY)

oirë

everlasting [?age]

oirë noun "everlasting [?age]" (Reading of gloss uncertain)(OY)

tennoio

adverb. forever, forever[more]

@@@ used for “forever” in NQNT

Quenya [UT/305; UT/317] Group: Eldamo. Published by

íra

eternal

[íra adj. "eternal" (GEY, VT45:13; changed by Tolkien to oira, see OY)]

írë

eternal

[írë] (3) noun "eternal" (read "eternity", as suggested by Christopher Tolkien, but the word was in any case changed to oirë)(GEY, VT45:13)