hereditarian Syllabification: (he·red·i·tar·i·an)Pronunciation: /həˌrediˈte(ə)rēən/Definition of hereditarian adjective of or relating to the theory that heredity is the primary influence on human behavior, intelligence, or other characteristics. noun an advocate of a hereditarian view. Derivatives hereditarianismPronunciation: /-əˌnizəm/ noun hereditarian in other Oxford dictionaries Definition of hereditarian in the British & World English dictionary