Thesaurus

abject, acerb, acerbic, acid, acrid, afflictive, amort, anguished, awful, awkward, beastly, bereaved, bereft, bitter, black, blistering, blue, brokenhearted, calamitous, caustic, chapfallen, cheerless, chopfallen, clumsy, crestfallen, cumbersome, dark, deflated, dejected, depressed, depressing, dingy, disaffected, disastrous, disconsolate, discontent, discontented, disgruntled, dismal, dispirited, dispiriting, displeased, displeasing, dispossessed, dissatisfied, distressed, dolorous, dolourous, doomed, dour, down, down in the mouth, downcast, downhearted, downtrodden, drab, dreadful, drear, dreary, dysphoric, elegiac, embarrassing, fatal, fateful, forbidding, funereal, gloomy, glum, god-awful, grief-stricken, grieving, grievous, grim, hapless, harsh, heartbreaking, heartbroken, heartrending, heartsick, hellish, homeless, homesick, hot, ill-affected, ill-chosen, ill-fated, ill-natured, ill-omened, ill-starred, inapt, inept, infelicitous, joyless, lachrymose, lamenting, lonely, lonesome, long-faced, lovesick, low, low-spirited, luckless, lugubrious, malcontent, melancholy, mirthless, miserable, misfortunate, mortifying, mournful, mourning, nasty, nostalgic, offensive, painful, pathetic, piteous, pitiable, pitiful, plaintive, poor, rebarbative, rebellious, regrettable, repellant, repellent, restless, roofless, rough, sad, sepulchral, sharp, sharp-worded, somber, sombre, sore, sorrowful, sorrowing, sorry, suffering, sulfurous, sulphurous, tart, tearful, too bad, tormented, tortured, unamused, uncheerful, underprivileged, unfortunate, ungrateful, ungratified, unhappy, unlucky, unpalatable, unpleasant, unsatisfied, unsmiling, unsuccessful, venomous, virulent, vitriolic, wailful, wailing, weeping, woebegone, woeful, wretched

unhappy is a ADJ.