invasion
A military action consisting of a large armed force of one geopolitical entity entering territory controlled by another such entity, generally with the objective of conquering territory or altering the established government.
Other meanings
The entry without consent of an individual or group into an area where they are not wanted.
“an invasion of mobile phones”
The spread of cancer cells, bacteria and such to the organism.
Word history
From Latin "invāsiōnem".
Where this comes from
This definition is adapted from “invasion” on Wiktionary, by its contributors, published under CC BY-SA 4.0. This page is published under the same licence.