UXO stands for Unexploded Ordnance. It refers to any explosive weapon—such as bombs, bullets, shells, grenades, or mines—that was used during a conflict or training exercise but failed to detonate as intended.
These remnants of war, though seemingly inactive, pose a significant danger even decades after being abandoned. They can remain hidden underground, underwater, or scattered across landscapes, waiting to be disturbed and potentially explode, causing serious injury or death.