Of course the definition is a little loose. But the main point is though; it is the remnant that comes into place after a period of destruction.
If you have a dream in which you see a lot of debris it means that you are thinking about the past a little too much. You are too concerned with things that have taken place far in the past and that cannot be changed because of how far away they are and how far removed you are from them. To get past these dreams you need to think more about what really happened in the past and about how you can really get ahead in life. If you have this dream it is also a good indication that you are getting older and your memories are starting to seem farther and farther away from you.
As stated above, debris is something that always appears after an accident or a tragedy. So therefore if you see a lot of debris this must mean a wreck or something has happened. Perhaps you are seeing visions of miles and miles of debris in your sleep because you think that your life has been a wreck or perhaps you have had an accident recently of a more social nature or something that you did wrong which could have been done better. If this is the case then this may be why you’re dreaming of debris.