invade

verb

1. 1

   march aggressively into another's territory by military force for the purposes of conquest and occupation

   Hitler invaded Poland on September 1, 1939

2. 2

   penetrate or assault, in a harmful or injurious way

   The cancer had invaded her lungs

3. 3

   to intrude upon, infringe, encroach on, violate

   This new colleague invades my territory

   The neighbors intrude on your privacy

4. 4

   occupy in large numbers or live on a host

   the Kudzu plant infests much of the South and is spreading to the North