Noun phrase.
/deˈfen.sa de ˈflan.ko/
"Defensa de flanco" is a term commonly used in military contexts. It refers to the defense of a flank, which is the side of a military formation. This term is more frequently used in written military documents and discussions than in everyday oral speech.
The defense of the flank is crucial in this operation.
Es importante tener en cuenta la estrategia de defensa de flanco en el campo de batalla.
"Defensa de flanco" is not an idiomatic expression per se, but it is often used in military idioms in Spanish.
We are in a situation of flank defense, we must prepare ourselves.
La defensa de flanco es una de las maniobras más delicadas en combate.
"Defensa" comes from the Latin "defensa" and "flanco" from the Latin "flancus," both meaning "side."