坍塌，崩溃

1. collapse, crumbling, breaking down, caving in

noun (common) (futsuumeishi) noun or participle which takes the aux. verb suru intransitive verb

（放射性）衰变，解体

2. (radioactive) decay, disintegration

noun or participle which takes the aux. verb suru noun (common) (futsuumeishi) intransitive verb physics