Passbooks rhymes with:
checkbooks, cookbook's, cookbooks, guidebooks, handbooks, jokebooks, matchbooks, notebooks, overbooks, pocketbooks, schoolbooks, scrapbooks, sketchbooks, storybooks, textbooks, waldenbooks, waldenbooks', yearbooks
Passbooks sounds like:
pacific, pacific's, pacifica, pacifico, pago_pago, passbook, paysops, pickups, piggyback, poughkeepsie, poughkeepsie's, push-ups, pushups