A joke that is understood by only those who work or play together. """Would you like to buy some of our liveware?"" I asked. She frowned. ""Never mind,"" I said. ""It's an inside joke. Ha ha."""
An in-joke (also known as an in joke or inside joke) is a joke whose humor is clear only to those people who are "inside" a social group, occupation or other community of common understanding; an esoteric joke. It is only humorous to those who know the situation behind it. Inside jokes may exist within a small social clique, such as a group of friends. They also may extend to an entire profession (e.g., inside jokes in the film industry)