Disintegration is when one thing splits into parts or just ceases to exist. When something is destroyed, broken up into pieces, or falls apart on its own, that’s disintegration.
If you know that integration brings things or people together, you won't be surprised that disintegration means things are coming apart. Disintegration is what happens when a company breaks into smaller companies or when a band splits up. Often, disintegration is physical — a bomb could cause the disintegration of its target. The decomposition (rotting) of a body is an example of disintegration. When something radioactive decays, that's disintegration, too. Disintegration is when it all falls apart.