mitogen Syllabification: (mi·to·gen)Pronunciation: /ˈmītəjən/Definition of mitogen noun Physiology a substance that induces or stimulates mitosis. Derivatives mitogenicPronunciation: /ˌmītəˈjenik/ adjective Origin: 1960s: from mitosis + -genmitogen in other Oxford dictionaries Definition of mitogen in the British & World English dictionary