Definition of: invade

(in·vād′) v. ·vad·ed, ·vad·ing v.t.
1. To enter with or as with hostile intent, as for conquering or plundering.
2. To encroach upon; trespass on: to invade privacy.
3. To spread over or penetrate injuriously: Disease invaded the lungs.
—v.i.
4. To make an invasion. [<L invadere <in- in + vadere go]
—in·vad′er noun