invasion

American  

[in-vey-zhuhn] / ɪnˈveɪ ʒən /

noun

• invasions
  plural

1. an act or instance of invading or entering as an enemy, especially by an army.

2. the entrance or advent of anything troublesome or harmful, as disease.

3. entrance as if to take possession or overrun.

   the annual invasion of the resort by tourists.

4. infringement by intrusion.

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invasion British  

/ ɪnˈveɪʒən /

noun

1. the act of invading with armed forces

2. any encroachment or intrusion

   an invasion of rats

3. the onset or advent of something harmful, esp of a disease

4. pathol the spread of cancer from its point of origin into surrounding tissues

5. the movement of plants to a new area or to an area to which they are not native

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Other Word Forms

Derived Forms

• reinvasion
  noun
• preinvasion
  adjective

Inflected Forms

Nouns

• invasions
  plural

Etymology

Origin of invasion

1400–50; late Middle English < Late Latin invāsīon- (stem of invāsiō ), equivalent to invās ( us ), past participle of invādere + -iōn- -ion; see invade

Explanation

An invasion is the movement of an army into a region, usually in a hostile attack that's part of a war or conflict. World history is full of descriptions of invasions. One country's army plundering or taking over a city or piece of land in another country is an invasion. You can call other mass movements invasions as well, like a horrifying invasion of your kitchen by cockroaches, or the invasion of a stadium by excited soccer fans. A common phrase is "invasion of privacy," which means an unfair intrusion into someone's personal space or private information.

Example Sentences

See Examples For:

invasion invasions

Both agencies play a central role in Kyiv's war effort and have seen their powers massively grow during Russia's invasion.

From Barron's ● Sep. 4, 2026

Although Western countries ended direct air links after the invasion, airlines from many Middle Eastern and Asian countries have continued to fly to Russia.

From The Wall Street Journal ● Sep. 4, 2026

Driving along the wall that separates the two countries, we saw service roads built by Israel after the invasion, intense movement of Israeli soldiers and residential buildings that were being used by them.

From BBC ● Sep. 2, 2026

Burnham has largely focused on domestic policy since taking over, but has also appeared eager to project his standing on the international stage, in particular maintaining London's support for Ukraine following Russia's 2022 full-scale invasion.

From Barron's ● Sep. 2, 2026

But when the invasion of the foreigner came, they showed themselves for what they were, and thus Charles, King of France, was permitted to take Italy with a piece of chalk.

From "The Prince" by Niccolò Machiavelli

Last time a marine heatwave hit South Australia and Tasmania, there were starving penguins, fish kills, suffocating algae outbreaks, and jellyfish invasions.

From BBC ● Sep. 3, 2026

In both of these misguided invasions, Americans apparently convinced themselves that Canadians essentially did not exist, at least not as a people or a nation with a shared collective identity.

From Salon ● Aug. 31, 2026

Castro is remembered by supporters as having guided Cuba through multiple crises -- US-backed invasions, embargoes, assassination plots and the intense hardship caused by the collapse of Cuba's main ally and benefactor, the Soviet Union.

From Barron's ● Aug. 11, 2026

Since Russian President Vladimir Putin launched his full-scale invasion in 2022, following his covert invasions of Ukraine’s Crimean peninsula and eastern regions in 2014, Russian forces have captured roughly 12% of Ukraine’s territory.

From Los Angeles Times ● Jul. 6, 2026

It even turned out to be crucial for the D-Day invasions.

From "The Woman All Spies Fear" by Amy Butler Greenfield

Related Words

• aggression
• assault
• breach
• incursion
• infiltration
• infringement
• intrusion
• offensive
• onslaught
• raid
• violation