1. A person that accompanies you on a trip that does not necessarily have to be there, but insists so - like excess baggage.
2. A person that is not relevant to trip itself nor participates in the events of the trip; they are usually needed in times of comfort - like your carry-on baggage.
Person B: “Why? Anne doesn’t work for the same company as Sarah”
Person A: “No, I know - she’s just Sarah’s cabbagge”