Playpen rhymes with:
bullpen, airmen, biogen, bruntjen, bullpen, businessmen, canadienne, energen, euroyen, flagmen, gunmen, julianne, longden, mahen, mailmen, middlemen, minutemen, neupogen, nexgen, parisienne, powergen, repairmen, shenzhen, synergen, tiananmen, turkmen, uniden, urgen, valencienne, weathermen
Playpen sounds like:
pavlovian, philbin, philippine, philippino, phillabaum, phillipine, plebeian, plybon, polyolefin, polyphony