It can also imply a sense of:
* Emptiness: Feeling like there's nothing left in the world, or that everything is meaningless.
* Disillusionment: Having lost faith in the world or the people in it.
* Loneliness: Feeling disconnected from others and the world around you.
The exact meaning of "hueco mundo" can depend on the context. It's a phrase with a lot of emotional weight and evokes a feeling of despair and emptiness.