cas

noun. skull, skull, [G.] head

A noun appearing as G. cas “head, skull” in the Gnomish Lexicon of the 1910s, where Tolkien said it was “only used of physical head of bodies” (GL/25). It was clearly derived from the early root ᴱ√KASA “head” (QL/31). The word ᴱN. cas “skull” reappeared in Early Noldorin Word-lists of the 1920s (PE13/140). Given the tendency of non-initial s to vanish in later iterations of the language (something that was not a feature of Gnomish of the 1910s), Tolkien likely abandoned this word.

nod

noun. head