Noun

1. A substance or agent that can cause cancer.
   • 1995, Barbra Wiener, Executive Director Women's Cancer Resource Center Minneapolis, "Letter: Focus Cancer Research on Prevention," New York Times, 26 Oct. (retrieved 19 Oct. 2009):

     We know there are substances in our environment that are proven carcinogens—ionizing radiation, electromagnetic fields, organochlorines, pesticides and herbicides.