unhappy

Etymology

From Middle English unhappy; equivalent to un- + happy.

adj

1. Not happy; sad.
   A moment of time may make us unhappy forever. 1728, John Gay, The Beggar's Opera
2. Not satisfied; unsatisfied.
   An unhappy customer is unlikely to return to your shop.
3. (chiefly dated) Not lucky; unlucky.
   The doomed lovers must have been born under an unhappy star.
   The pointed shaft of the cart had entered the breast of the unhappy Prince like a sword, and from the wound his life's blood was spouting in a stream, and falling with a hiss into the road. 1891, Thomas Hardy, Tess of the d'Urbervilles, volume 1, London: James R. Osgood, McIlvaine and Co., page 56
4. (chiefly dated) Not suitable; unsuitable.

noun

1. An individual who is not happy.
   Leduc, as is true of many other unhappies, is largely a confessional writer: her subject is herself, and her gift is a driving, vivacious power that turns her incurable, inveterate unhappiness into a series of dramas […] 1972, The New Yorker (volume 48, part 1, page 109)