Grumpy rhymes with:
frumpy, bumpy, clumpy, dumpy, frumpy, jumpy, lumpy, bumpy, campi, campy, ciampi, clumpy, dumpy, empey, empie, frumpy, jumpy, lampi, lumpy, pompey, rampey, rampy, sampey, skimpy, stimpy, swampy, tempe, wimpee, wimpy
Grumpy sounds like:
granoff, greenup, grownup, grump