(physics, countable) A nuclear reaction with the emission of a gamma ray.

(programming) The conversion of an array variable into a pointer to its first element.

(dentistry) Dental caries.

plural of exponential decay

A decrease where the rate of decrease is proportional to the amount remaining.

(historic preservation) State of preservation where no attempt is made to improve a ruin, but rather to keep it from deteriorating any further.

A hypothetical process whereby spacetime undergoes a phase transition (decays) into a lower-energy state.

(finance) A second-order measure of derivative price sensitivity, expressed as the instantaneous rate of change of delta with respect to time.

Radioactive decay.

(creationism, pseudoscience) The discredited theory that the speed of light has decreased over time, proposed by creationists in order to support the belief that the universe is a few thousand years old even though there are objects visible today that are billions of light years away (whereas a constant speed of light would indicate that the universe is billions of years old and so contradict this belief).