invasion

noun

in·​va·​sion in-ˈvā-zhən 

1

: an act of invading

especially : incursion of an army for conquest or plunder

2

: the incoming or spread of something usually hurtful

Synonyms

• incursion
• raid

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

At least 2,400 American troops died during the invasion on Omaha Beach. —Chandelis Duster, NPR, 20 July 2025

When the Russian Federation launched its full-scale invasion of Ukraine in February 2022, the Russians turned to the CSTO for assistance. —Mark Temnycky, Forbes.com, 18 July 2025

The New York Times reports that climate change may catapult the mushrooms’ invasion even farther in North America, by making more areas of the continent increasingly habitable for the species. —Amber X. Chen, Smithsonian Magazine, 18 July 2025

The arrest comes at a pivotal moment for the U.S. and Russia, as President Donald Trump hardens his stance against Moscow after months of diplomatic engagement to end the Russian invasion of Ukraine. —Shane Croucher, MSNBC Newsweek, 18 July 2025

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

Phrases Containing invasion

• counter-invasion
• invasion of (someone's) privacy
• pre-invasion

Rhymes for invasion

• abrasion
• caucasian
• equation
• eurasian
• evasion
• occasion
• persuasion
• asian
• suasion
• athanasian

Kids Definition

invasion

noun

in·​va·​sion in-ˈvā-zhən 

: an act of invading

especially : entrance of an army into a country for conquest

Medical Definition

invasion

noun

in·​va·​sion in-ˈvā-zhən 

: 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 

: the act of or an instance of invading