Definition of Invade

• march aggressively into anothers territory by military force for the purposes of conquest and occupation; "Hitler invaded Poland on September 1, 1939"
• to intrude upon, infringe, encroach on, violate; "This new colleague invades my territory"; "The neighbors intrude on your privacy"
• occupy in large numbers or live on a host; "the Kudzu plant infests much of the South and is spreading to the North"