Rubble, wreckage, scattered remains of something destroyed.
"After the storm, piles of debris littered the street from uprooted trees and broken signs."
In plain English: Debris is any scattered pieces of broken material left over after something has been destroyed or damaged.
"The storm left piles of tree branches and broken glass as debris across the neighborhood street."
Usage: Debris refers to any scattered fragments or rubble left after destruction and is typically used as an uncountable noun rather than being pluralized with an 's'. You will often see it paired with words like "wreckage" when describing the aftermath of a disaster, but avoid using it for small, distinct items that can be easily counted individually.
The word debris comes from the French term for broken or crumbled material. It entered English with its current meaning of scattered wreckage rather than retaining a different original sense.