metagenesisPronunciation: /ˌmɛtəˈdʒɛnɪsɪs/Definition of metagenesis noun [mass noun] Biology the alternation of generations between sexual and asexual reproduction. Derivatives metageneticPronunciation: /-dʒɪˈnɛtɪk/ adjective Origin: late 19th century: modern Latinmetagenesis in other Oxford dictionaries Definition of metagenesis in the US English dictionary