A verb appearing in the Qenya Lexicon of the 1910s as fengin “I cut” under the early root ᴱ√FEŊE (QL/38).
Early Quenya
vilkin
adjective. bitter, evil
vilki-
verb. to cut
feng-
verb. to cut
narte
adjective. bitter
píqa
adjective. bitter
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 verb appearing in the Qenya Lexicon of the 1910s as vilkin “it cuts” under the early root ᴱ√VḶKḶ (QL/101).