Qenya
feren
noun. beech-tree
ferne
noun. beech-tree
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 word for “beech-tree” in The Etymologies of the 1930s with variants feren and ferne derived from primitive ᴹ✶pheren based on the root ᴹ√PHER(EN) “beech” (Ety/BERÉTH; PHER). Its plural form was ferni < ✱fer(e)nī due to the affect of the Quenya syncope. It is likely the variant singular ferne was based on this plural, with feren being the original singular form.
Conceptual Development: In Early Qenya of the 1910s and 20s, the word for “beech” was ᴱQ. neldor derived from the early root ᴱ√NELE point (QL/65; PE16/139). Later Tolkien decided S. neldor “beech” was Sindarin; see that entry for discussion.