Sinful rhymes with:
cranfill, disdainful, gainful, grenfell, mournful, painful, panful, scornful, stanfill, teaspoonful, tuneful
Sinful sounds like:
sample, sampley, sanville, schnabel, schnebly, seasonable, semple, shamble, shambley, shameful, simple, simply, sinopoli, snabel, snapple, snavely, sniffily, sniffle, snively, snowball, snowfall, snowmobile, snowplow, sunnyvale, symbol