Condensation which forms on the inside of the windows of a vehicle, esp. public transit in the winter. Can also refer to the thick humid air that fills a vehicle's cabin, resulting from many people exhaling in a confined space, such as a bus or train car.
Jim caught TB from all the lung juice he breathed in while riding the bus in the ghetto.
by acertainshape September 27, 2016
Get the Lung juice mug.