From Longman Business Dictionaryoverbankedo‧ver‧banked /ˌəʊvəˈbæŋkt◂ˌoʊvər-/ adjectiveBANKING if a city, area, country etc is overbanked, there are too many banks in relation to the number of customersIt is a hugely overbanked country - there are 80 banks for a population of 3.5 million. —overbanking noun [uncountable]The authorities could help solve the overbanking in the region by agreeing to the merger of these banks.
