Adjective unhappy has 4 senses
  1. unhappy - experiencing or marked by or causing sadness or sorrow or discontent; "unhappy over her departure"; "unhappy with her raise"; "after the argument they lapsed into an unhappy silence"; "had an unhappy time at school"; "the unhappy (or sad) news"; "he looks so sad"
    happy, blessed, blissful, bright, elysian, paradisiacal, paradisiac, paradisaical, paradisaic, paradisal, paradisial, golden, halcyon, prosperous, joyful, joyous, laughing, riant
  2. dysphoric, distressed, unhappy - generalized feeling of distress
  3. unhappy - causing discomfort; "the unhappy truth"
    pleasant (indirect, via unpleasant)
  4. infelicitous, unhappy - marked by or producing unhappiness; "infelicitous circumstances"; "unhappy caravans, straggling afoot through swamps and canebrakes"- American Guide Series
    Antonym: fortunate (indirect, via unfortunate)