A verb for “steal” in the Qenya Lexicon of the 1910s based on the early root ᴱ√NAQA of similar meaning (QL/64).
Early Quenya
pili-
verb. to steal
pilin
noun. feather; arrow
naqa-
verb. to steal
pilna
noun. arrow
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 as ᴱQ. pili- “steal” in the Qenya Lexicon of the 1910s under the early root ᴱ√PILI “rob” (QL/74).
Neo-Quenya: I would retain ᴺQ. pil- “to steal, ✱rob” for purposes of Neo-Quenya as the best of the attested verbs meaning “steal”. For example, this verb was used in Helge Fauskanger’s NQNT (NQNT).