A noun appearing as G. pibin “small berry, haw” in the Gnomish Lexicon of the 1910s (GL/64), clearly a cognate to ᴱQ. pi(o)pin “fruit of hawthorns, haws” (QL/74).

Neo-Sindarin: The Early Qenya word was related to ᴱ√PINI “*small” and there is evidence that *√PI(N) continued to mean “small” in Tolkien’s later writing. Therefore, I’d retain ᴺS. pibin for purposes of Neo-Sindarin, used of any small berry but more specifically the berries of hawthorns.