Webster's Revised Unabridged Dictionary · 1913

Invade

Invade , transitive verb

[Latin invadere, invasum; pref. in- in + vadere to go, akin to English wade: compare Old French invader, French envahir. See Wade.]

1.
To go into or upon; to pass within the confines of; to enter; -- used of forcible or rude ingress. [Obsolete]
Which becomes a body, and doth then invade The state of life, out of the grisly shade. — Spenser
2.
To enter with hostile intentions; to enter with a view to conquest or plunder; to make an irruption into; to attack; as, the Romans invaded Great Britain.
Such an enemy Is risen to invade us. — Milton
3.
To attack; to infringe; to encroach on; to violate; as, the king invaded the rights of the people.
4.
To grow or spread over; to affect injuriously and progressively; as, gangrene invades healthy tissue.

Invade , intransitive verb

To make an invasion. — Brougham