macroevolution Syllabification: (mac·ro·ev·o·lu·tion)Pronunciation: /ˌmakrō-evəˈlo͞oSHən, -ˌēvə-/Definition of macroevolution noun Biology major evolutionary change. The term applies mainly to the evolution of whole taxonomic groups over long periods of time. Derivatives macroevolutionaryPronunciation: /-SHəˌnerē, -ˌēvə-/ adjective macroevolution in other Oxford dictionaries Definition of macroevolution in the British & World English dictionary