Noah Webster
Irruption
IRRUP'TION, noun [Latin irruption; in and rumpo, to break or burst.]
1. A bursting in; a breaking or sudden violent rushing into a place. Holland has been often inundated by irruptions of the sea.
2. A sudden invasion or incursion; a sudden, violent inroad, or entrance of invaders into a place or country; as the irruption of the northern nations into France and Italy.