cordillera, (from old Spanish cordilla, “cord,” or “little rope”), a system of mountain ranges that often consist of a number of more or less parallel chains. Cordilleras are an extensive feature in the Americas and Eurasia. In North America the Rocky Mountains, the Sierra Nevadas, and the mountains between them are collectively known as the Cordilleras, and the entire area has been termed the Cordilleran region. The term Cordillera is used with a directional modifier (e.g., Cordillera Oriental) to differentiate the various chains of the Andes Mountains as they extend through Colombia, Venezuela, Bolivia, and other countries in South America.