Words That Rhyme With "Frightful" :

2 syllables:

doubtful, eyeful, fateful, fitful, hateful, hatful, nightfall, pipeful, plateful, potful, rightful, sighful, snootful, spiteful, sprightful, thoughtful

3 syllables:

deceitful, delightful, despiteful, foresightful, forethoughtful, forgetful, insightful, unthoughtful