The word ᴱQ. rent (renty-) “spittle, saliva” appeared in the Qenya Lexicon of the 1910s under the early root ᴱ√RET͡YE (QL/79). In Early Noldorin Word-lists of the 1920s Tolkien had ᴱQ. rekka as a cognate of ᴱN. crech “spittle” from primitive ᴱ✶kǝ̀rekka (PE13/140).
Neo-Quenya: I’d retain ᴺQ. recca “spittle, ✱saliva” for purposes of Neo-Quenya.