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

People familiar with the company’s operations say Hengli has been buying sanctioned oil since at least late 2020, with purchases expanding after Russia’s invasion of Ukraine in 2022.

From The Wall Street Journal ● Aug. 16, 2026

Yasukuni is dedicated to 2.5 million war dead, mostly Japanese, including convicted war criminals involved in Imperial Japan's invasion and occupation of parts of Asia in the 1930s and 1940s.

From Barron's ● Aug. 15, 2026

Concerns over how the war in Ukraine would affect global food supplies have been persistent since the start of Russia's invasion in 2022.

From BBC ● Aug. 12, 2026

He said: "Harold's policy on the papacy may ultimately have played into the hands of his enemies, giving William's opportunistic invasion the legitimacy of a just war."

From Science Daily ● Aug. 11, 2026

In October, a combined Austrian-German-Bulgarian invasion finally succeeded in crushing Serbia, occupying the kingdom and driving the defeated remnants of the Serbian army out completely.

From "The War to End All Wars: World War I" by Russell Freedman

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

Kagan insists that the Fourth Amendment cannot be defeated by slicing invasions of privacy into pieces small enough to appear constitutionally insignificant.

From Slate ● Jun. 29, 2026

Who knew chairs could tell stories of invasions and class hierarchies?

From BBC ● Mar. 13, 2026

Rumors run rampant—there are false reports of parachute invasions, gas attacks, and spy infiltrations.

From "At Last She Stood" by Erin Entrada Kelly

Related Words

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