Thesaurus

abhorrent, acerb, acerbic, acid, acrid, afflictive, atrabilious, awful, bad-tempered, beastly, bilious, bitter, blistering, brackish, bristly, cantankerous, caustic, charnel, choleric, churlish, crabbed, crabby, cranky, creepy, cross, crotchety, crusty, curmudgeonly, currish, dark, detestable, dirty, disagreeable, disconcerting, disgustful, disgusting, displeasing, distasteful, dour, dreadful, dyspeptic, embarrassing, evil, exasperating, filthy, forbidding, foul, fractious, fussy, ghastly, ghoulish, glowering, glum, god-awful, grim, grotty, grouchy, gruff, grumpy, harsh, hateful, hellish, hideous, horrid, horrific, hot, hot-tempered, hotheaded, huffish, ill-humored, ill-humoured, ill-natured, ill-tempered, inedible, infuriating, irascible, irritable, liverish, loathly, loathsome, lousy, maddening, mean, misanthropic, misanthropical, misogynous, moody, morbid, morose, mortifying, nagging, nasty, nettlesome, objectionable, obnoxious, obscene, off-putting, offensive, ornery, outrageous, painful, peckish, peevish, pettish, petulant, prickly, quick-tempered, rank, rebarbative, repellant, repellent, repelling, repugnant, repulsive, revolting, rough, saturnine, scratchy, scrimy, sepulchral, sharp, sharp-worded, shirty, short-tempered, shrewish, skanky, snappish, snappy, snorty, sore, sour, splenetic, spoiled, spoilt, sulfurous, sulky, sullen, sulphurous, surly, tart, tasteless, techy, testy, tetchy, ugly, unappetising, unappetizing, uneatable, ungrateful, unhappy, unpalatable, unpleasant, unsavory, unsavoury, upsetting, venomous, verminous, vexing, vinegarish, vinegary, virulent, vitriolic, waspish, wicked, yucky

unpleasant is a ADJ.