invasion

noun

in·​va·​sion in-ˈvā-zhən How to pronounce invasion (audio)
1
: an act of invading
especially : incursion of an army for conquest or plunder
2
: the incoming or spread of something usually hurtful

Examples of invasion in a Sentence

The enemy launched an invasion. The people live under a constant threat of invasion. The town is gearing up for the annual tourist invasion. protecting the house from insect invasion
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Neither side confirmed the local truce, but Ukraine’s energy ministry said Ukrainian specialists were working to restore the power lines on Saturday, the 42nd round of repair works since Russia’s full-scale invasion. Caitlin Danaher, CNN Money, 18 Oct. 2025 Despite months of military build-up, the escalation into a full-scale Russian invasion of Ukrainian territory in February 2022 and the subsequent imposition of sweeping and continuously expanding sanctions came as a major shock to thousands of transnational corporations. Emma Burleigh, Fortune, 18 Oct. 2025 Trump reportedly asked advisers in 2019 about a military invasion of Venezuela during a meeting about sanctions against Maduro. Cybele Mayes-Osterman, USA Today, 18 Oct. 2025 Washington has recently appeared to grow more amenable to resuming military backing for Kyiv’s push to repel Russia’s invasion. Ben Smith, semafor.com, 17 Oct. 2025 See All Example Sentences for invasion

Word History

Etymology

Middle English invasioun "assault, attack," borrowed from Anglo-French invasion, envasioun, borrowed from Late Latin invāsiōn-, invāsiō "attack, taking possession by violence," from Latin invādere "to enter with hostile intent, assault, attack" + -tiōn-, -tiō, suffix of verbal action — more at invade

First Known Use

15th century, in the meaning defined at sense 1

Time Traveler
The first known use of invasion was in the 15th century

Browse Nearby Words

Cite this Entry

“Invasion.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/invasion. Accessed 21 Oct. 2025.

Kids Definition

invasion

noun
in·​va·​sion in-ˈvā-zhən How to pronounce invasion (audio)
: an act of invading
especially : entrance of an army into a country for conquest

Medical Definition

invasion

noun
in·​va·​sion in-ˈvā-zhən How to pronounce invasion (audio)
: the act of invading: as
a
: the penetration of the body of a host by a microorganism
b
: the spread and multiplication of a pathogenic microorganism or of malignant cells in the body of a host

Legal Definition

invasion

noun
in·​va·​sion in-ˈvā-zhən How to pronounce invasion (audio)
: the act of or an instance of invading

More from Merriam-Webster on invasion

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!