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

• descent
• foray
• incursion
• inroad
• irruption
• 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

The researchers had been galvanized by Russia’s full-scale invasion of Ukraine, in February, 2022. —Keith Gessen, The New Yorker, 10 Jan. 2025

The city is known worldwide as the site of a Russian massacre early in the 2022 invasion. —Joanna Kakissis, NPR, 10 Jan. 2025

Trump's return to the White House on Jan. 20 has sparked hope of a diplomatic resolution to end Moscow's invasion but also fears in Kyiv that a quick peace could come at a high price for Ukraine. —Trevor Hunnicutt, USA TODAY, 9 Jan. 2025

Other pundits also said Trump’s rhetoric validated Russia’s invasion of Ukraine. —Colin Meyn, The Hill, 9 Jan. 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

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