Noun

• S: (n) fifth column, Trojan horse (a subversive group that supports the enemy and engages in espionage or sabotage; an enemy in your midst)
• S: (n) trojan, trojan horse (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"
• S: (n) Trojan Horse, Wooden Horse (a large hollow wooden figure of a horse (filled with Greek soldiers) left by the Greeks outside Troy during the Trojan War)