Frightening rhymes with:
brightening, brightening, enlightening, heightening, lightening, tightening, battening, brightening, captaining, disheartening, enlightening, fattening, flattening, heartening, heightening, lightening, shortening, smartening, straightening, sweetening, threatening, tightening
Frightening sounds like:
fabricating, fabrications, farsightedness, firestone's, forecasting, foreshadowing, forgetting, fractions, frictions, frightens, frosting, frostings