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

Polish and allied forces shot down at least three UAVs for the first time since Russia’s full-scale invasion of Ukraine in 2022. —Bloomberg News, Boston Herald, 13 Sep. 2025

In the opening months of the full-scale invasion of Ukraine in 2022, the Bayraktar TB2 drone system enabled the Ukrainian military to destroy large Russian columns of equipment. —Joseph Nepomuceno, The Washington Examiner, 13 Sep. 2025

The third season of Apple’s big alien invasion series continues to drop episodes each week. —Erik Kain, Forbes.com, 13 Sep. 2025

Defense investment landscape 'unrecognisable' Since Russia's full-scale invasion of Ukraine in early 2022, private capital has been pouring into European defense firms. —Chloe Taylor, CNBC, 12 Sep. 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