overpopulation UK /ˌəʊvəˌpɒpjʊˈleɪʃn̩/US /ˌoʊvɚˌpɑpjəˈleɪʃ(ə)n/ noun1 •An excessive number of occupants (people, animals, plants, etc.) in a particular area; specifically, when the number of occupants exceeds the ability of that area to provide for them.When it comes to overpopulation as the cause of wildlife loss in Africa, Prince William just won't let it go. — 2021 formsoverpopulations