So what does "freedom" mean?

The important thing to note is that "freedom" invariably applies to inter-human relationships. Freedom does not relate in any significant way to the human condition in a solitary state.

To better understand what this means, imagine that an individual lives alone on an isolated island. How he came to be there is not important, except that he was not involuntarily placed there by any other human being. The vegetation and creatures on the island easily provide for his needs, and he has no particular desire to be elsewhere.

The question of freedom for this individual does not arise. He is obviously free. The word would have no particular significance to him.

Suppose that this man were struck by lightning, or trapped by a falling tree, and unable to move.

He would not think, "I have lost my freedom." Rather, he would conclude that he had been injured, and immobilized, by an accident, or a random act of nature.

Or suppose he decides that he would like to see what lies beyond the island. He would not consider himself to have "lost" his freedom in any way, regardless of what may be his present lack of ability to leave his present location.