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

The city -- home to more than 710,000 people before Russia's full-scale invasion -- is now only around 16 miles from the front line and subject to continuous Russian attacks. —David Brennan, ABC News, 28 Sep. 2025

The Ukrainian leader’s remarks come as his country is under martial law, imposed since Russia’s full-scale invasion started in February 2022. —Emma Bussey, FOXNews.com, 26 Sep. 2025

Even as Israel has launched a major invasion of Gaza City, Hamad offered little indication that Israel’s military pressure is impacting the group’s core negotiating positions. —Jeremy Diamond, CNN Money, 26 Sep. 2025

The titular robotic dinosaurs are machines piloted by humans who, in the new series, must defend Earth from a monstrous alien invasion trying to resurrect its prehistoric army. —Andrew McGowan, Variety, 25 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