The feeling of not being happy

plural of unhappiness

Not happy; sad. / Not satisfied; unsatisfied. / (chiefly dated) Not lucky; unlucky. / (chiefly dated) Not suitable; unsuitable.

An individual who is not happy.

comparative form of unhappy: more unhappy

(obsolete) Made unhappy.

plural of unhappy

(medicine) An injury to the anterior cruciate ligament, medial collateral ligament, and medial meniscus.

plural of unhappy triad