Qenya
piuta-
verb. to spit
pis-
verb. to spit
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 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.