invade
verb.
march aggressively into another's territory by military force for the purposes of conquest and occupation
Hitler invaded Poland on September 1, 1939
Synonym: occupy
verb.
to intrude upon, infringe, encroach on, violate
This new colleague invades my territory|The neighbors intrude on your privacy
verb.
occupy in large numbers or live on a host
the Kudzu plant infests much of the South and is spreading to the North
Synonym: infest, overrun
verb.
penetrate or assault, in a harmful or injurious way
The cancer had invaded her lungs