monogenesis Syllabification: (mon·o·gen·e·sis)Pronunciation: /ˌmänəˈjenəsəs/Definition of monogenesis noun the theory that humans are all descended from a single pair of ancestors. Also called monogeny. Linguistics the hypothetical origination of language or of a surname from a single source at a particular place and time. Derivatives monogeneticPronunciation: /-jəˈnetik/ adjective monogenesis in other Oxford dictionaries Definition of monogenesis in the British & World English dictionary