"trivial talk, nonsense," 1865, American English, probably from Dutch dialect pappekak, from Middle Dutch pappe "soft food" (see pap) + kak "dung," from Latin cacare "to excrete" (from PIE root *kakka- "to defecate").
popliteal
popover
popper
poppet
poppy
poppycock
Popsicle
popster
populace
popular
popularise