prediction vs. prognostication
preconception vs. prepossession
psychiatry vs. psychopathology
palaeontology vs. paleontology
palaeoanthropology vs. paleoanthropology
palaeodendrology vs. paleodendrology
prosthodontia vs. prosthodontics
palaeozoology vs. paleozoology
palaeornithology vs. paleornithology
palaeobiology vs. paleobiology
palaeogeology vs. paleogeology
palaeoecology vs. paleoecology
palaeoclimatology vs. paleoclimatology
palaeogeography vs. paleogeography
palaeopathology vs. paleopathology
protoanthropology vs. protohistory
protoarchaeology vs. protoarcheology
palaeoethnography vs. paleoethnography
provincialism vs. sectionalism
particularisation vs. particularization