trojan horse Meaning, Definition & Usage

1. noun a subversive group that supports the enemy and engages in espionage or sabotage; an enemy in your midst
   fifth column.
   
2. noun a program that appears desirable but actually contains something harmful
   trojan.
   
   • 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
3. noun a large hollow wooden figure of a horse (filled with Greek soldiers) left by the Greeks outside Troy during the Trojan War
   Wooden Horse.
   

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