pipeclay

n [U] fine white clay used (esp formerly) for making tobacco pipes and for whitening leather, etc 白陶土（尤於旧时用以制烟斗、 使皮革增白等）.

pinnacle, pinnate, pinny, pinpoint, pinprick, pins and needles, pint, pint-sized, pinto, pioneer, pioneering, pious, piously, piousness, pip, pip-squeak, pipal (also peepul), pipe, pipe-cleaner, pipe-dream, pipeline, piper, pipette, piping, pipit, pippin, piquancy, piquant, piquantly, pique, piquet, piracy, piranha, pirate, piratical, piratically, pirouette, Pisa, piscatorial, Piscean,