Qenya
ilurambar
proper name. Walls of the World
vai(y)a
noun. envelope
There are more words but they are from Tolkien's earlier conceptional periods. Tolkien likely changed these words as he evolved the aesthetics and completeness of the languages. You may even find languages that Tolkien later rejected. Do not mix words from different time periods unless you are familiar with the phonetic developments.
Below: Tolkien's Late Period (1950–1973). These are from Tolkien's late conceptual period — his most settled forms of the languages. Prefer these over the earlier ones above when composing new text.
A noun for “envelope” in The Etymologies of the 1930s with forms vaia or vaiya, and derived from ᴹ✶wāyā under the root ᴹ√WAY of similar meaning (Ety/WAY). It was used “especially of the Outer Sea or Air enfolding the world within the Ilurambar or world-walls”. It was also the name of a tengwar consisting of a circle with line leading from its bottom out horizontally to the right (EtyAC/WAY), but this tengwar did not appear in The Lord of the Rings.