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

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

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