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 of invasion

• 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

Python removal programs remain the most effective way to slow the invasion, but finding the snakes is painstaking, time-eating work. — Ashley Miznazi, Miami Herald, 2 July 2026

Inspired by the alien invasion genre and slacker hang out movies, the film is about a group of friends standing up against an alien invasion that threatens to swallow the whole world. — Alison Foreman, IndieWire, 2 July 2026

The invasion of Canada As 1775 wore on, force came to join careful letters. — Sarah M.s. Pearsall, The Conversation, 2 July 2026

By way of example, Bäte notes that Allianz did not fully foresee the speed with which interest rates rose after Russia’s full invasion of Ukraine in 2022. — Andrew Edgecliffe-Johnson, semafor.com, 3 July 2026

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