Gropper rhymes with:
cropper, dropper, improper, proper, propper, bopper, chopper, clopper, copper, cropper, dropper, hopper, improper, kopper, opper, popper, proper, propper, shopper, stopper, topor, topper, whopper
Gropper sounds like:
garber, garver, geographer, gerber, grabber, graber, graeber, graper, graver, greber, greever, grever, griever, grober, groover, grouper, groupware, grover, gruber, gruver