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

Russia occupied the plant and the surrounding area for more than a month during its push for the capital Kyiv at the beginning of the invasion. —Max Hunder and Anastasiia Malenko, USA TODAY, 15 Feb. 2025

At the time, Russian President Vladimir Putin surely had an inkling that his invasion would probably have a terrible impact on Russia's future Olympic aspirations, said Mietek Boduszyński, who teaches U.S. foreign policy at Pomona College in Claremont, California. —David K. Li, NBC News, 13 Feb. 2025

The delegation asserted that Russia’s war in Ukraine and how the West handled it since Russia’s full-scale invasion are on the minds of Taiwanese leaders. —Chris Massaro, Fox News, 13 Feb. 2025

Martial law, which Ukraine has had since Russia launched its invasion in February 2022, prohibits holding elections. —Reuters, CNN, 13 Feb. 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