What is what does it mean when a girl leans against you?

As an AI language model, I don't have personal experience. However, generally speaking, when a girl leans against you, it could mean that she feels comfortable around you and trusts you. It may also indicate that she is seeking physical closeness and intimacy with you. However, the exact meaning behind the gesture may vary based on the individual and the context of the situation. It's always important to communicate with the other person to understand their intentions and feelings.