carcinogen

n. substance or agent that causes cancer

The term carcinogen refers to any substance, radionuclide or radiation which is an agent directly involved in the promotion of cancer or in the facilitation of its propagation. This may be due to genomic instability or to the disruption of cellular metabolic processes. Several radioactive substances are considered carcinogens, but their carcinogenic activity is attributed to the radiation, for example gamma rays or alpha particles, which they emit. Common examples of carcinogens are inhaled asbestos and tobacco smoke.
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Noun
1. any substance that produces cancer
(hypernym) substance, matter

A substance or agent that is known to cause cancer.

[kar-SIN-o-jin]
Any substance that causes cancer.