Merriam-Webster New Collegiate Dictionary

 

 

de-cay’  v.i. [deriv of Latin de + cadere to fall]

 

1.  To pass gradually from a sound or prosperous state to one of imperfection, adversity, or dissolution; waste away.

 

 

 

Question:  Do unstable individual nuclides decay, or do they disintegrate in pristine condition, with only their numbers wasting away?