v., -vad·ed, -vad·ing, -vades. v.tr.
- To enter by force in order to conquer or pillage.
- To encroach or intrude on; violate: "The principal of the trusts could not be invaded without trustee approval" (Barbara Goldsmith).
- To overrun as if by invading; infest: "About 1917 the shipworm invaded the harbor of San Francisco" (Rachel Carson).
- To enter and permeate, especially harmfully.
To make an invasion: "The X-rays showed that the cancer, which had invaded deeply into the chest cavity, was retreating" (Zach Rosen).
[Middle English, from Old French invader, from Latin invādere : in-, in; see in-2 + vādere, to go.]
invader in·vad'er n.




