"Freedom's just another word for nothing left to lose." There's a grain of truth in that song, though I don't think it provides any useful description.
Freedom involves a very basic level of autonomy for individuals. Freedom in a society involves guarantees of that basic level of autonomy for individuals in meaningful fashion; one is free to travel, for example, only if one can reasonably expect to actually accomplish travel, that one can accumulate the resources readily to achieve the travel. If one has a nominal right to travel yet will never be able to do so due to participation in a system that won't allow one to gather the resources to travel, then one isn't actually free to travel.
I think Amartya Sen (Nobel laureate economist) had the right of it in his book "Freedom as Economic Development." Granted, there are components to freedom that aren't economic in nature, though to enjoy the full benefits of those in large part rests on having the resources available to do so.