n. 1. The act of invading, especially the entrance of an armed force into a territory to conquer. 2. The entry into bodily tissue and subsequent proliferation of an injurious entity, such as a pathogen or tumor. 3. An intrusion or encroachment: Your reading her diary was an invasion of her privacy. [Middle English invasioun, from Old French invasion, from Late Latin invāsiō, invāsiōn-, from invāsus, past participle of invādere, to invade; see INVADE.] |
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