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.