Dushnila
From the word "dushniy" (душный), a Russian word for the person who makes the atmosphere in the room "stuffy" by correcting small mistakes/telling detailed stuff about the topic that is not interesting for anyone/whining/always trying to prove their point
"This person is such a dushnila, he was talking about this *any not interesting topic* the whole evening!"
"- You should've used here the word efficient instead of effective.
- You're dushnila"
"- You should've used here the word efficient instead of effective.
- You're dushnila"