Found 2 items, similar to fifth column.
English → English (WordNet) Definition: fifth column fifth column n : a subversive group that supports the enemy and engages in espionage or sabotage; an enemy in your midst [syn: Trojan horse ]
English → English (gcide) Definition: fifth column fifth column \fifth` col"umn\, n. [from a statement during the Spanish Civil War (1936) that the Falange had four columns of soldiers marching on the city, and a fifth column “already there” (i.e. sympathizers inside the Republican lines).] 1. a group of persons inside the battle lines of a territory engaged in a conflict, who secretly sympathize with the enemy, and who engage in espionage or sabotage; -- sometimes also referred to as a trojan horse. [RP] 2. Hence, any faction of persons within a group who secretly sympathize with an enemy, especially those who engage in activities harmful to the group; an enemy in one's midst; a group of traitors. [RP]