-ë

-ë combined with lengthening of the stem-vowel is used to derive what is properly verbal nouns. Sometimes the sense of the derived words drifts from pure abstract to the more concrete, denoting an object or phenomenon that is produced by the corresponding verb.

Examples

nútë = "knot" (nut- = "to tie")
lírë = "song" (lir- = "to sing") ^[1]
sírë = "river" (sir- = "to flow")

Other Uses

-ë is also used as a feminine ending in antë = "[female] giver" (ant- = "to give"; ANA)^[2]

References

↑ J.R.R. Tolkien, "Words, Phrases and Passages in Various Tongues in The Lord of the Rings", in Parma Eldalamberon XVII (edited by Christopher Gilson)
↑ J.R.R. Tolkien, Christopher Tolkien (ed.), The Lost Road and Other Writings, Part Three: "The Etymologies", p. 348

[1] J.R.R. Tolkien, "Words, Phrases and Passages in Various Tongues in The Lord of the Rings", in Parma Eldalamberon XVII (edited by Christopher Gilson)

[2] J.R.R. Tolkien, Christopher Tolkien (ed.), The Lost Road and Other Writings, Part Three: "The Etymologies", p. 348

[1]

[2]