killjoy (noun)

1. During the festival, the killjoy preacher stood outside the temple, condemning the revelers' behavior.

2. In the 18th century, the British government labeled John, the leader of the rebellious group, a killjoy and severely punished him.

3. In Greek mythology, the god of wine Dionysus punished those who insulted him by turning them into killjoys, forever unable to enjoy celebrations.

4. When Mark proposed on a beautiful moonlit beach, Sarah's killjoy sister pointed out all the reasons why their marriage would never work.