1. total destruction

e.g. bomb tests resulted in the annihilation of the atoll

Synonym: annihilation

2. the spontaneous disintegration of a radioactive substance along with the emission of ionizing radiation

Synonym: decayradioactive decay

3. separation into component parts

Synonym: dissolution

4. in a decomposed state

Synonym: decomposition

5. a loss (or serious disruption) of organization in some system

e.g. a disintegration of personality