Early Primitive Elvish
retye
root. *spit
kereke
root. *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.
A root appearing in the Gnomish Lexicon of the 1910s with variants ᴱ√kerek- and ᴱ√kereχ- and derivatives like G. crech “spittle”, G. crectha- “spit”, G. agrectha- “despise”, and G. agrectharol “despicable” (GL/27). The first of these derivatives reappeared in Early Noldorin of the 1920s as a derivative of ✶kǝ̀rekka along with the Qenya form ᴱQ. rekka (PE13/140). This Qenya form, and the meaning of the Gnomish words from the 1910s, resembles the derivatives of the root ᴱ√RETYE from the Qenya Lexicon of the 1910s such as ᴱQ. retye- “spit” and ᴱQ. retima “despicable” (QL/79). Thus ᴱ√KEREKE may be variant or replacement for ᴱ√RETYE.
In The Etymologies of the 1930s there is a later root ᴹ√PIW “spit” which may have supplanted ᴱ√K(E)REKE, but the derivatives of ᴹ√PIW are only verbal and I think it worth positing the existence of a Neo-Eldarin noun root ᴺ√K(E)REK “spittle” to salvage the Gnomish words, especially those having to do with contempt.