What is another word for invasion?
Pronunciation: [ɪnvˈe͡ɪʒən] (IPA) 
Invasion is the act of entering a territory or domain without prior permission or invitation. Some synonyms for invasion include encroachment, infiltration, incursion, and trespass. Encroachment refers to the gradual intrusion of one group onto the property or territory of another. Infiltration is the process by which something such as an idea or subculture seeps into an established group or system. An incursion refers to an attack or intrusion into a country or territory, often by military force. Trespass is a legal term referring to the act of entering or using someone else's property without permission.
Overall, all these synonyms depict the act of intruding or penetrating a territory or domain without the owner's knowledge or consent.
