fifth column

American  

noun

1. a group of people who act traitorously and subversively out of a secret sympathy with an enemy of their country.

2. (originally) Franco sympathizers in Madrid during the Spanish Civil War: so called in allusion to a statement in 1936 that the insurgents had four columns marching on Madrid and a fifth column of sympathizers in the city ready to rise and betray it.

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fifth column British  

noun

1. (originally) a group of Falangist sympathizers in Madrid during the Spanish Civil War who were prepared to join the four columns of insurgents marching on the city

2. any group of hostile or subversive infiltrators; an enemy in one's midst

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fifth column Cultural  

1. People willing to cooperate with an aggressor against their own country. The term originated in a remark by Francisco Franco, the Spanish dictator, that he was marching on Madrid with four columns of troops, and that there was a “fifth column” of sympathizers within the city ready to help.

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fifth column Idioms  

1. A secret subversive group that works against a country or organization from the inside, as in The government feared that there was a fifth column working to oppose its policies during the crisis. This term was invented by General Emilio Mola during the Spanish Civil War in a radio broadcast on October 16, 1936, in which he said that he had una quinta columna (“a fifth column”) of sympathizers for General Franco among the Republicans holding the city of Madrid, and it would join his four columns of troops when they attacked. The term was popularized by Ernest Hemingway and later extended to any traitorous insiders.

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Other Word Forms

• fifth columnist noun

Example Sentences

In fact, because many children didn’t show symptoms of the infection or had only mild, flu-like symptoms, they functioned almost like an undetected fifth column in spreading the virus to adults.

From Los Angeles Times

He lauded protesters and spoke directly to soldiers, telling them the war was illegal, perhaps hoping to inspire a fifth column — a term for groups of internal resisters, open or clandestine.

From Los Angeles Times

He paints his Jewish opponents as weak, self-hating “leftists,” and Arab politicians as a potential fifth column of terrorist sympathizers.

From Seattle Times

That hostile takeover maneuvers very much like a fifth column, operating in a highly calculated fashion, more akin to an occupying force than to an open group engaged in the usual give-and-take of politics.

From Salon

Though King said he has mellowed with age — he turned 40 recently — Beau’s very moniker nods to his ideology: A fifth column is a double-agent who seeks to sabotage a group or country from within.

From Los Angeles Times