Trojan horse

noun

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 3

See Trojan horse defined for English-language learners

See Trojan horse defined for kids

Examples of trojan horse in a Sentence

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

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.

Origin and Etymology of trojan horse

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

NEW! Time Traveler

First Known Use: 1837

in the meaning defined at sense 1

See Words from the same year

TROJAN HORSE Defined for English Language Learners

Trojan horse

noun

Definition of Trojan horse for English Language Learners

: 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