cas ("k")"head" (VT49:17), cf. also deleted [cas] ("k")noun "top, summit" (VT45:19). This noun should evidently have the stem-form car-. See cár.
Element in: Q. carma
cár (cas-) ("k")noun "head" (KAS).The given stem-form appears doubtful within the phonological framework of LotR-style Quenya. Probably we should read cas with stem car- (PE14:69 indeed reads "kas head, pl. kari", and VT49:17 quotes the sg. "kas" from a post-LotR source). Compare other forms found in late sources: hlas "ear" with stem hlar- (PE17:62) and olos "dream", pl. olori (UT:396). In Tolkiens early "Qenya", post-vocalic -s became -r at the end of words but was preserved when another vowel followed. His later scheme either lets -r appear in both positions, or reverses the scenario altogether (hence olos, olor-). It would seem that the forms cár, cas- were distractedly carried over into the Etymologies from the Qenya Lexicon (kar, kas-, QL:45) even though they presuppose an earlier version of the phonology. An apparent variant form in late material, cára from earlier cáza ("k"), however fits the later phonology since intervocalic s would become z > r (PE17:188).