A person or thing that
gets in the way; a burden that you are stuck with.
Example:
1) Ed wants to leave his wife and kids - he feels like they are just excess baggage.
Etymology:
When you fly on a plane, there are limits
on how much luggage (or how many suitcases or bags) you can bring with
you. Anything over the limit is called 'excess baggage' (or extra bags)
and cannot be put on the plane.