adj. 25B6; adjective
an unhappy childhood : SAD, miserable, sorrowful, dejected, despondent, disconsolate, morose, broken-hearted, heartbroken, down, downcast, dispirited, downhearted, depressed, melancholy, mournful, gloomy, glum, despairing, doleful, forlorn, woebegone, woeful, long-faced, joyless, cheerless; informal down in the mouth/dumps, fed up, blue.
in the unhappy event of litigation : UNFORTUNATE, unlucky, luckless; ill-starred, ill-fated, doomed; informal jinxed; poetic/literary star-crossed.
I was unhappy with the service I received : DISSATISFIED, displeased, discontented, disappointed, disgruntled.
disorganized capitalism seems an unhappy term : INAPPROPRIATE, unsuitable, inapt, unfortunate; regrettable, ill-chosen.
cheerful.