Polder rhymes with:
beholder, bolder, boulder, colder, dolder, folder, golder, holder, molder, moulder, nolder, older, shoulder, smolder
Polder sounds like:
paltry, pelletier, peltier, pfleiderer, plater, platter, plethora, plotter, polidori, polidoro, polluter, poulter, poultry