Radioactive

/ˌreɪdi.oʊˈæk.tɪv/

Meaning & Definition

adjective

Emitting or relating to the emission of ionizing radiation or particles.

Uranium is a radioactive element used in nuclear fuel.

Capable of undergoing radioactive decay, leading to the emission of radiation.

Radon is a naturally occurring radioactive gas found in basements.

Describes materials or substances that emit radiation as a result of nuclear reactions.

The radioactive waste must be stored securely to prevent contamination.

From the combination of 'radio-' meaning ray, and 'active' meaning capable of action.

radioactive waste

Waste that contains radioactive material and poses a potential threat to the environment.

radioactive decay

The process by which an unstable atomic nucleus loses energy by radiation.

radioactive isotope

An isotope that is unstable and emits radiation.

radiation

The emission of energy as electromagnetic waves or as moving subatomic particles.

nuclear

Relating to the nucleus of an atom, often involving energy release.

Glow-in-the-dark

That watch is so radioactive, it practically glows in the dark!

Intensely exciting or dangerous

That party was radioactive; it was wild!