English to English
noun
- a subversive group that supports the enemy and engages in espionage or sabotage; an enemy in your midst
source: WordNet 3.0
- a program that appears desirable but actually contains something harmful
The contents of a trojan can be a virus or a worm.
When he downloaded the free game it turned out to be a trojan horse.
source: WordNet 3.0
- a large hollow wooden figure of a horse (filled with Greek soldiers) left by the Greeks outside Troy during the Trojan War
source: WordNet 3.0