invasion

Invasion, n.

Etymology: [L. invasio: cf. F. invasion. See Invade.]

1. The act of invading; the act of encroaching upon the rights or possessions of another; encroachment; trespass.

2. A warlike or hostile entrance into the possessions or domains of another; the incursion of an army for conquest or plunder.

3. The incoming or first attack of anything hurtful or pernicious; as, the invasion of a disease.

Syn. -- Invasion, Irruption, Inroad. Invasion is the generic term, denoting a forcible entrance into a foreign country. Incursion signifies a hasty and sudden invasion. Irruption denotes particularly violent invasion. Inroad is entry by some unusual way involving trespass and injury.

Shades of meaning

Fernald has no entry of its own for invasion; he lists it under attack.

Where he writes about it:

An invasion of a nation's territories is an act of aggression; an intrusion upon a neighboring estate is a trespass. — from attack

Synonyms

attack aggression assault encroachment incursion infringement intrusion onset onslaught trespass

Antonyms

defense repulsion resistance retreat submission surrender

etymology Webster’s online