incursion

American  

[in-kur-zhuhn, -shuhn] / ɪnˈkɜr ʒən, -ʃən /

noun

1. a hostile entrance into or invasion of a place or territory, especially a sudden one; raid.

   The bandits made brief incursions on the village.

   Synonyms:

   attack, foray, sortie

2. a harmful inroad.

3. a running in.

   the incursion of sea water.

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incursion British  

/ ɪnˈkɜːsɪv, ɪnˈkɜːʃən /

noun

1. a sudden invasion, attack, or raid

2. the act of running or leaking into; penetration

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Other Word Forms

• incursive adjective

Etymology

Origin of incursion

1400–50; late Middle English < Latin incursiōn- (stem of incursiō ) raid, equivalent to incurs ( us ) (past participle of incurrere to incur ) + -iōn- -ion; excursion

Explanation

When an army crosses a border into another country for battle, they are making an incursion into enemy territory. An incursion is an invasion as well as an attack. Incursion can also be used to describe other things that rush in like an army such as an invasive species into a new region or floodwaters entering your home. When an airplane heads onto a runway it is not supposed to land on, risking airport safety, it is known as a runway incursion. And an incursion of cold air could make September feel like December.

Example Sentences

Seoul initially denied any official role in the January drone incursion -- with authorities suggesting it was the work of civilians -- but Lee said a probe had revealed government officials had been involved.

From Barron's • Apr. 6, 2026

Completely marginalized during the administration’s Venezuela incursion, she was not even being invited to the White House Situation Room to observe the operation.

From Salon • Mar. 22, 2026

The military told all residents of a huge swathe of southern Lebanon near the Israeli border to leave on Wednesday, ahead of a much-anticipated ground incursion.

From BBC • Mar. 5, 2026

Officials have not publicly confirmed whether Kurdish groups will mount cross-border operations, but security analysts say an incursion into Iranian territory could open a new front in the conflict.

From Los Angeles Times • Mar. 5, 2026

Faced with the possibility of disrupting their favored position as middlemen, the Narragansett might think twice before staging an incursion.

From "1491" by Charles C. Mann

Related Words

• aggression
• attack
• foray
• infiltration
• inroad
• intrusion
• penetration
• raid