yéniënoun “annal(s)”; Yénië Valinórëo “Annals of Valinor” (MR:200)
yen, yendënoun "daughter" (YŌ/YON). This word replaced another form, but this form may have been restored; see yeldë. In VT45:16, yendë is said to refer to a female "agent", a word changed by Tolkien from yendi, but Tolkien deleted all of this.
[yendi] noun "agent" (fem.; masc. [hendo]). The word yendiTolkien changed to yendë before deleting all of this (VT45:16)
yenyanoun (or adv.?) "last year" (YA)
yëorelative pronoun in genitive "from whom" (could also mean *"of whom"); see ye # 1.
yérënoun *"sexual desire" (VT46:23; the word is not really glossed, but looks like an abstract formation from the stem YER "feel sexual desire")
yernaadj. "old, worn" (GYER)
yerya- vb. "to wear (out)", also intr. "get old" (GYER)
yesta- (1) vb. "desire" (YES, VT46:23; the latter source indicates that Tolkien did write yesta- with a final hyphen, indicating that this is "desire" as a verbal stem, not as a noun).