gossip
Casual talk about other people’s private lives, often as rumors.
Gossip means casual talk about other people's private lives, especially when they're not around to hear it. When you gossip, you're sharing information about what someone said, did, or what might have happened to them. At lunch, students might gossip about who sits with whom, who got in trouble, or who might have a crush on someone.
Gossip isn't always mean, though it often turns that way. Sometimes it's just curiosity: wondering why your friend seemed upset yesterday or hearing that your neighbor got a new puppy. But gossip becomes harmful when it spreads rumors that might not be true, shares secrets people wanted kept private, or judges others behind their backs.
The word can also be a noun meaning a person who loves to gossip. If someone's known as a gossip, they have a reputation for constantly talking about others' business.
People sometimes think about whether sharing information helps anyone or just entertains them at someone else's expense. There's a big difference between mentioning that your friend broke their arm (so others can sign their cast) and speculating about why two classmates aren't talking anymore.