radioactive decay

The second type, especially helium, forms as a byproduct of radioactive decay, processes that are still happening.

Before anti-vaxxers, there were anti-fluoriders: a group who spread fear about the anti-tooth decay agent added to drinking water.

As a means of preventing tooth decay in those cities that do fluoridate, the practice certainly looks like a success.

Their decay proceeded without a ready supply of oxygen, producing hydrocarbons like methane instead of oxygen-bearing molecules.

Political Order and Political Decay Francis Fukuyama (Farrar, Straus, and Giroux) How are strong democratic states created?

A drawing of what was deemed a “deer pig” was also sent through the uranium decay ringer.

The General in command of the station was a feeble old man, suffering from senile decay.

It will hold tenaciously there, the last of its race, days after the decay of its greener and more healthy-looking mates.

The decay and ruin of nearly all the "old families" in Ireland are among the penalties of disregarding it.

The old dining-hall had shared in the general decay, and been shorn of all its ancient honours.

It is likewise formed daring the decay of animal and vegetable matters, and is consequently evolved from dung and compost heaps.