The crossword solution for the term 'WINDOW's Counterpart' is AISLE, which has five letters. An AISLE is a long, narrow passage or corridor that is typically found in a public building such as a church, theater, or supermarket. It is usually separated from other areas by rows of seats or shelves. Aisles are also commonly found in airplanes and other forms of transportation. AISLE is the counterpart to WINDOW because it provides a way for people to move around a space, just like a WINDOW provides a way to look out into the world.