Cusack

Cusack is an Irish family name of Norman origin ''Cussacq'', which is originally from Cussac in Guienne (Aquitaine), France. The surname has diminished in common use in England, but is still common in Ireland, where it was introduced during the Norman invasion of Ireland in the 12th century.

While Cusack is not a particularly common name, it is often historically associated with a number of variant forms, such as de Cussac, de Cusack, de Ciusak, de Cíosóg, de Cíomhsíg, Mac Íosóg, and Mac Isog.

Cusack, Kuzak, Kuzack, Cusick, and Cussack are all modern day variants of this name. Provided by Wikipedia