In·vade v. t. [imp. & p. p. Invaded; p. pr. & vb. n. Invading.]
 1. To go into or upon; to pass within the confines of; to enter; -- used of forcible or rude ingress. [Obs.]
 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.
 Syn: -- To attack; assail; encroach upon. See Attack.