Thesaurus

Synonyms for Dreadful include:

abominable, acerb, acerbic, acid, acrid, afflictive, alarming, appalling, atrocious, awful, bad, baleful, beastly, bitter, blistering, bloodcurdling, caustic, chilling, corked, corky, crappy, creepy, creepy-crawly, deplorable, dire, direful, dismaying, disobedient, displeasing, distressing, dour, dread, dreaded, dreadful, embarrassing, evil, fearful, fearsome, forbidding, formidable, frightening, frightful, ghastly, god-awful, grim, grisly, gruesome, hair-raising, hairy, hard, harsh, hellish, hopeless, horrendous, horrible, horrid, horrific, horrifying, hot, icky, ill, ill-natured, incompetent, lamentable, lousy, macabre, mediocre, menacing, minacious, minatory, mischievous, mortifying, nasty, naughty, negative, nightmarish, no-good, offensive, ominous, painful, petrifying, pitiful, poor, pretty, rebarbative, redoubtable, repellant, repellent, rotten, rough, rubber, sad, scarey, scary, severe, sharp, sharp-worded, shivery, shuddery, sick, sinister, sore, sorry, stinking, stinky, stupefying, sulfurous, sulphurous, swingeing, tart, terrible, terrific, terrifying, threatening, tough, ugly, uncool, unfavorable, unfavourable, ungrateful, unhappy, unnerving, unpalatable, unpleasant, unskilled, unspeakable, unsuitable, venomous, virulent, vitriolic, worse, worst

dreadful is a ADJ.