killjoy

/ˈkɪlˌdʒɔɪ/
noun
  1. A person who spoils the enjoyment or fun of others, often by being overly serious or critical.
    • The teacher was called a killjoy when she canceled the class party because of a few noisy students.
    • Don't be such a killjoy—let the kids stay up a little later for the fireworks.
    • My friend is a bit of a killjoy at parties; he always complains about the music.
What does "killjoy" mean? | whatsthatwordmean | whatsthatwordmean