fifth column

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.

fifth column

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

fifth column

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.

Other Word Forms

• fifth columnist noun

Idioms and Phrases

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.

Example Sentences

These include the disruption of Taiwan's communication lines; Chinese disinformation campaigns; "fifth column" supporters of China stirring up unrest; and military officials turned collaborators who conspire against Taiwan.

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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.

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He was hoping that a "fifth column" of ethnic Germans there would become a useful aid in the military.

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He has accused opposition parties of acting as a "fifth column" directed from abroad, and described President Zourabichvili as a a "chief agent".

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The interview is "really quite sad," Clinton continued, because it's a sign that some Americans at this moment "are like a fifth column from Vladimir Putin."

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