Words That Rhyme With "Helpfully" :
3 syllables:
4 syllables:
distressfully, forgetfully, regretfully, successfully
5 syllables:
acrocephaly, anencephaly, brachycephaly, cymbocephaly, hydrocephaly, hypsicephaly, isocephaly, macrocephaly, microcephaly, oxycephaly, scaphocephaly, unsuccessfully