1. The act of invading; the act of an army that invades for conquest or plunder
   "The Norman invasion of England in 1066 changed the course of British history"
    
2. Any entry into an area not previously occupied
   "an invasion of locusts";
   - encroachment, intrusion
    
3. (pathology) the spread of pathogenic microorganisms or malignant cells to new sites in the body
   "the tumour's invasion of surrounding structures"

Derived forms: invasions

Type of: entrance, incursion, penetration, spread, spreading

Encyclopedia: Invasion, Planeshift, Apocalypse