The excessive provision of banks or banking facilities; the granting of charters to an excessive number of banks, especially when this results in bank failures.
Early 19th century; earliest use found in The North American Review. Either from over- + banking, or from over- + bank + -ing.
The action of overbank .
Late 19th century; earliest use found in Frederick Britten (1843–1913). From overbank + -ing.