1. (

• invade ,
• occupy

) march aggressively into another's territory by military force for the purposes of conquest and occupation; "Hitler invaded Poland on September 1, 1939" ;

2. (

• intrude_on ,
• invade ,
• obtrude_upon ,
• encroach_upon

) to intrude upon, infringe, encroach on, violate; "This new colleague invades my territory"; "The neighbors intrude on your privacy" ;

3. (

• invade ,
• overrun ,
• infest ,

) occupy in large numbers or live on a host; "the Kudzu plant infests much of the South and is spreading to the North" ;

4. (

• invade

) penetrate or assault, in a harmful or injurious way; "The cancer had invaded her lungs" ;