Noah Webster's New International Dictionary of the English Language

1. (a.) Not happy or fortunate; unfortunate; unlucky; as, affairs have taken an unhappy turn.

2. (a.) In a degree miserable or wretched; not happy; sad; sorrowful; as, children render their parents unhappy by misconduct.

3. (a.) Marked by infelicity; evil; calamitous; as, an unhappy day.

4. (a.) Mischievous; wanton; wicked.