To run upwards on an
escalator going the opposite direction. In other words, running upwards against an escalator headed down. Typically,
dropboxing is done on extended escalators such as those found in many large US cities, such as the ones providing access to the Washington,
D.C. metro rail.
Jim and Tony were really sore after a late night out ended with the two
dropboxing the
Chinatown metro to impress Kathy and
Diane.