An apparent verb in The Etymologies of the 1930s derived from the root ᴹ√PIW “spit” and so probably of the same meaning (Ety/PIW).

Conceptual Development: The earliest verb for “spit” was ᴱQ. retye- from the Qenya Lexicon of the 1910s under the early root ᴱ√RET͡YE (QL/79). In the Early Qenya Grammar of the 1920s Tolkien had ᴱQ. piste “spit” from primitive ᴱ✶pṣt- (PE14/58), a verb that also appeared in the contemporaneous Early Noldorin Dictionary as a cognate of ᴱN. hist- “spit” (PE13/163). The next “spit” verb was ᴹQ. piuta- in The Etymologies of the 1930s (see above), and in the 1948 Quenya Verbal System Tolkien had ᴹQ. pise from the root ᴹ√PITH “spit” (PE22/103).

Neo-Quenya: For purposes of Neo-Quenya, I prefer 1930s ᴹQ. piuta- “spit”, in part because it is better known that 1948 pith- but also because it has a Noldorin cognate N. puia- and is thus part of a more complete paradigm.