Early Primitive Elvish
fana
root. *dream, vision
fṇðṇ
root. *omen, ominous
olo
root. *dream
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.
An unglossed root in the Qenya Lexicon of the 1910s, first given as ᴱ√FANA but then changed to ᴱ√FṆÐṆ (QL/38). It had derivatives such as ᴱQ. fando “portent, omen” and ᴱQ. fandelu “monster”, so it perhaps had a basic sense like “✱omen, ominous”. One notable derivative was ᴱQ. Fantor used a collective name for Lórien and Mandos (QL/38; LT1/79). In later writings this name became ᴹQ. Fantur “Lord of Cloud” (Ety/SPAN) and then Q. Fëanturi “Masters of Spirits” (S/28), making it likely this early root was abandoned.