microfauna Syllabification: (mi·cro·fau·na)Pronunciation: /ˌmīkrōˈfônə, -ˈfänə/Definition of microfauna noun (plural microfaunas or microfaunae /-ˈfônē, -ˈfänē/) Biology microscopic animals. Derivatives microfaunal adjective microfauna in other Oxford dictionaries Definition of microfauna in the British & World English dictionary