A noun appearing as G. nanc “a bite” in the Gnomish Lexicon of the 1910s (GL/59), clearly based on the early root ᴱ√NAKA “bite” (QL/64).

Neo-Sindarin: Since ᴹ√NAK “bite” appeared in Tolkien’s later writings, I’d retain the noun ᴺS. nanc “bite” for purposes of Neo-Sindarin.