buzzkill
/ˈbʌzkɪl/Definitions
1. noun
A person or thing that spoils the fun or excitement of a social gathering or event by being boring or annoying.
“The new boss was a total buzzkill at the company party, and everyone was disappointed.”
2. verb
To spoil the fun or excitement of a social gathering or event by being boring or annoying.
“Stop being such a buzzkill and let everyone have fun!”