s as z.

A hostile entrance into the possessions of another; particularly, the entrance of a hostile army into a country for the purpose of conquest or plunder, or the attack of a military force. The north of England and south of Scotland were for centuries subject to invasion, each from the other. The invasion of England by William the Norman, was in 1066.

An attack on the rights of another; infringement or violation.

Attack of a disease; as the invasion of the plague, in Egypt.