The Foundary was a factory in Waterford where everyone's grandfather used to work. It was located down by the kay river. They used to pronounce it in this way due to the peculiar gutteral r sound of the old Waterford accent.
Used as an exclamation at something happening. Eg. at a hurling match when a person scores a goal in a humurous way a person can joke.
"Did ya see that, Up she flew and the cock flattened her!"