Propping rhymes with:
cropping, dropping, chopping, copping, cropping, dropping, flopping, hopping, lopping, mopping, popping, shopping, sopping, stopping, swapping, topping, wapping, whopping
Propping sounds like:
parfums, perfumes, perfuming, peruvians, pervomaiskaya, prepaying, prepping, previewing, probing, proofing, propionic, provance, provenance, provence, provencio, provenience, provenza, province, province's, provinces, proving, purifying, purveying, purviance