It can mean many things in many situations. An 'outgoing president', for example, is a president coming to the end of his ( or indeed her) term of office. Or if you describe a person's character as outgoing, it means that this person is extrovert and sociable, for example, 'We are looking for a friendly, outgoing person to join our team.'

An artillery shell whistles overhead our position. "Incoming!" shouts the lieutenant. "No, that's outgoing," I reply.

Outgoing > 2 meanings (adjective) 1. friendly and sociable and fun to be with > Don't worry . You will find him outgoing / I want an outgoing person to join me on my trip . 2. (A person) leaving a position/office or leaving a place > The outgoing manager will be replaced soon/ All outgoing buses to that place are halted due to the weather