adjective

radioactive

radioactive

Uranium is a radioactive element.

Uranium is a radioactive element.

Radioactive waste must be stored safely.

Radioactive waste must be stored safely.

radioactive ((noun)) describing something that emits radiation. Uranium is a radioactive element.

Synonyms: radiating, emitting; Antonyms: stable, inert

From 'radio-' (from Latin 'radius', 'ray') + 'active'. Literally 'active in emitting rays'.

Think of it as being 'active' by sending out 'radio' waves or rays.

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