Gossip is when we say to someone that we have no right to say. It might be true and we might know that it is true, but it may be secret or private. We may have agreed to keep silent, or signed a contract saying that we would keep silent. In any case, gossip is wrong because we have no right to say something that we are saying.
It follows that simply being true is not enough to give us the right to say something. If it did, then spreading secrets could never be wrong. But we all know that it is wrong. There are two elements that make it wrong. First, it is sharing a truth. Merely knowing it does not count as gossip. Second, it is sharing that truth with someone when you have no right to share it. Sharing what is publicly known is acceptable because we have a right to know those kind of things. Anything that satisfies both conditions counts as gossip and is wrong.
But how do we determine whether or not someone has a right to know something? There is no easy test. But first we would need to clarify the nature of rights in this case. There are three ways that rights may affect speech. First, the person may have a right to know the information. If you were a doctor and discovered that they were ill, then all other things being equal, you would have a duty to tell them they were sick. Second, the person may not have a right to know, but you may be permitted to tell them. Public facts and most information in the world falls into this category. Third, the person may not have a right right to know and you have a duty not to tell them. Telling them anyway would be gossip. Failing to tell someone that has the right to know something is a different fault.
From we know that there are rights related to speech and they can be violated in two different ways. If we tell someone something we have no right to share, then we violate this rights in one way. If fail to tell someone when they have a right to know, then we violate these rights in a different way.
All of these rights are about specific people and specific items of knowledge. Each right has one person who is told the knowledge, the knowledge they are told and the person who tells them that knowledge. Each right is either positive and the person ought to be told that knowledge or negative and the person ought not to be told that knowledge.
These distinctions enable us to further answer the question of speech, but it is probably better to examine other aspects of speech before continuing with this particular one. Next, I will discuss lying and deception.