Mammoth Uncensored Word List:
64 words ending with ps, 4 letters long

alps amps apps asps baps bops caps cops cups dips dups fops gaps gips gups gyps haps heps hips hops hups imps japs keps kips kops laps leps lips lops maps mops naps neps nips oops oups paps peps pips pops pups raps rips saps seps sips sops sups taps tips tops tups umps urps waps wops yaps yeps yips yups zaps zeps zips