A noun for “thief” in the Qenya Lexicon of the 1910s, an agental formation based on ᴱQ. naqa- “steal” (QL/64).
Early Quenya
pilu
noun. thief, robber
naqar
noun. thief
pilmo
noun. thief, robber
Beware, older languages below! The languages below were invented during Tolkien's earlier period and should be used with caution. Remember to never, ever mix words from different languages!
A noun appearing as ᴱQ. pilu “thief, robber” in the Qenya Lexicon of the 1910s under the early root ᴱ√PILI “rob”, along with a longer variant pilmo (pilmu-) (QL/74).
Neo-Quenya: Since I retain ᴺQ. pil- “to steal, ✱rob” for purposes of Neo-Quenya, I would retain ᴺQ. pilu “thief, robber” as well. For example, this noun was used in Helge Fauskanger’s NQNT (NQNT). A later noun of similar meaning is Q. arpo “seizer, thief”.