My definition of gossip is talking about a person by name. Some teachers gossip about as much as they breathe. They love talking about how good or bad particular students are. If they don't have a student to talk about then they will gossip about what other teachers are doing. This drives me crazy.
Gossiping about students and other teachers can create a negative atmosphere in the room, and eventually in an entire school. Some people don't even like being talked about in a positive way (especially when it comes to grades). I have a rule against naming names in my classroom, and if I was a principal I would have the same rule for my teachers. Don't use other people's business as your form of entertainment. Terrible.