What is Invader?

Invader definition and meaning on Dictionary terms:
verb (used with object), inA.vadA.ed,
to enter forcefully as an enemy; go into with hostile intent: Germany invaded Poland in 1939.
to enter like an enemy: Locusts invaded the fields.
to enter as if to take possession: to invade a neighbor’s home.
to enter and affect injuriously or destructively, as disease: viruses that invade the bloodstream.
to intrude upon: to invade the privacy of a family.

to encroach or infringe upon: to invade the rights of citizens.
to permeate: The smell of baking invades the house.
to penetrate; spread into or over: The population boom has caused city dwellers to invade the suburbs.

verb (used without object), inA.vadA.ed,
to make an invasion: troops awaiting the signal to invade.