Mammoth Uncensored Word List:
69 words ending with ps, 13 letters long

aldermanships assessorships attorneyships bachelorships brinkmanships cardinalships chairmanships championships chaplainships chimneysweeps coauthorships consumerships convenerships convenorships corporalships corrivalships counterscarps craftmanships creatureships deemsterships dictatorships directorships discipleships examinerships executorships followerships freshmanships gamesmanships governorships graduateships guardianships helmsmanships horsemanships huntsmanships laureateships listenerships marksmanships mediatorships ministerships musicianships overlordships partisanships partizanships preacherships prenticeships protoceratops quaestorships receiverships recorderships relationships residentships retainerships salesmanships seigniorships sergeantships serjeantships servitorships sinecureships spinsterships superiorships surveyorships survivorships underdevelops unfriendships virtuosoships viscountships watermanships weatherstrips wranglerships