Trojan horse


Definition of Trojan horse

1 : someone or something intended to defeat or subvert from within usually by deceptive means
2 : a seemingly useful computer program that contains concealed instructions which when activated perform an illicit or malicious action (such as destroying data files) also : the concealed instructions of such a program — compare virus sense 3

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Did You Know?

After besieging the walls of Troy for ten years, the Greeks built a huge, hollow wooden horse, secretly filled it with armed warriors, and presented it to the Trojans as a gift for the goddess Athena, and the Trojans took the horse inside the city's walls. That night, the armed Greeks swarmed out and captured and burned the city. A Trojan horse is thus anything that looks innocent but, once accepted, has power to harm or destroy—for example, a computer program that seems helpful but ends up corrupting or demolishing the computer's software.

Examples of Trojan horse in a Sentence

They may be using the other corporation as a Trojan horse.

First Known Use of Trojan horse

1837, in the meaning defined at sense 1

History and Etymology for Trojan horse

from the large hollow wooden horse filled with Greek soldiers and introduced within the walls of Troy by a stratagem

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Learn More about Trojan horse

Dictionary Entries near Trojan horse


Trojan asteroid

Trojan group

Trojan horse

Trojan War



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Time Traveler for Trojan horse

The first known use of Trojan horse was in 1837

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More Definitions for Trojan horse

Trojan horse


English Language Learners Definition of Trojan horse

: someone or something that is used to hide what is true or real in order to trick or harm an enemy
computers : a seemingly useful computer program that is actually designed to harm your computer (such as by destroying data files) if you use it

More from Merriam-Webster on Trojan horse

Rhyming Dictionary: Words that rhyme with Trojan horse

Nglish: Translation of Trojan horse for Spanish Speakers

Comments on Trojan horse

What made you want to look up Trojan horse? Please tell us where you read or heard it (including the quote, if possible).


to spread over or through

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