Mammoth Uncensored Word List:
78 words ending with p, 13 letters long

assistantship associateship barristership brinksmanship candidateship chieftainship churchmanship coadjutorship cocreatorship colleagueship collectorship commandership committeeship companionship conductorship confessorship constableship containership copartnership cosponsorship councilorship counselorship craftsmanship craftsmenship custodianship disfellowship draftsmanship gentlemanship gladiatorship grantsmanship homeownership housewifeship housewifeskep imperatorship indentureship inspectorship justiciarship landownership librarianship moderatorship nondealership nonmembership ombudsmanship pendragonship physicianship ploughmanship possessorship postulantship precentorship preceptorship presbytership presidentship pretendership principalship proconsulship professorship prosectorship protectorship registrarship rumbledethump scrivenership secretaryship seneschalship solicitorship spectatorship spokesmanship sportsmanship statesmanship subdeaconship subeditorship succentorship successorship suffraganship surrogateship swordsmanship treasurership tribesmanship yachtsmanship