Wise words, Crossnote.
I think gossip is when a second party talks to a third person about the first person - pastor, leader or congregation
It gives the first person no chance to respond and it is not Biblical.
"They were filled with all manner of unrighteousness, evil, covetousness, malice. They are full of envy, murder, strife, deceit, maliciousness. They are gossips, 30 slanderers, haters of God, insolent, haughty, boastful, inventors of evil, disobedient to parents," Romans 1:29-30
However, I once was in a church where the pastor was totally off course. He had abandoned the Bible completely and was preaching from books and claiming it was a word from God. For years!
A few of us talked quietly about the situation. Then he ousted a long time member and his wife. (The reason was because this man was arguing about which chord to play on the guitar in a worship song, and the pastor took it as an attack on his son. I was there and nothing bad happened!) Then more people left. Finally, I talked to him directly and told him that he simply was not preaching the Bible anymore. I asked him if he intended to change that, and he denied my charge. I left the church. People continued to leave the church. That pastor finally had to get a part time job, because so little money was coming in.
Meanwhile, half the church was displaced, looking for a home. The ones who stayed agreed with us that the pastor had gone off track. But no one really seriously "talked" about what he was doing. I guess to avoid the charge of gossip.
He destroyed that church, and drove many people from God. How much better if we had had a congregational meeting and openly discussed our concerns? How much better if he had been given an ultimatum to either preach the Bible or he would be replaced?
I think there may be valid times to discuss leadership, like in my example. That is not gossip, but rather working together to prevent bad from happening to a congregation.