noun

incursion

in-KUR-zhuhn/ɪnˈkɜːrʒn/

An entry into a place or area of activity, often without permission.

The raiders make an incursion across the defended boundary.

A small group of unmarked historical raiders crosses a defended boundary suddenly; distant non-graphic hostile entry, no named ethnicity, real conflict or tactical details.

Etymology

inLatininto, upon

+cursLatinto run

+ionLatinaction

The pieces evoke running into or against something. The Latin verb also meant to rush at or attack, giving the noun its image of a hostile entry.

In context

Gustavus Adolphus College29:07

the spaniard's first incursion into Mexico City tenet San ended in disaster for the Spaniards they had to fight their way out of the city and lost half their number

Alfred Crosby - The History of Infectious Disease as a Characteristic of Civilization

More examples

The company made an incursion into a new market.
Residents objected to the incursion onto protected land.
The episode marked a brief incursion into unfamiliar territory.

Forms

incursion · incursions

Similar words

invasion: An invasion is a larger or more sustained entry; an incursion can be brief or limited.
foray: A foray is a short venture into an area; incursion often suggests an unwelcome entry.