Some words beginning with P and ending with K:
packparkpeckpeekpeakperkpickporkpockpunkpuck
park, punk, pick, prank, pack, pork, pink, peacock, plank
atop
The curse word that starts with "p" and ends in "k" is likely "prick."
peacock
pizzazz.
Pies
pill
pill pencil
prohibiter
bookshop
pedophile