The phrase "double barn doors" refers to two large, wooden doors that are typically used for entering and exiting a barn or other outbuilding. These doors are often made from solid wood planks and feature horizontal slats, giving them a distinctive appearance with two long panels that slide along rails on either side of the doorway. The term "double" refers to the fact that there are actually two of these large wooden doors installed in the opening, providing easy access for vehicles or equipment entering and leaving the building.