(sports) The sport of riding on the roof, sides or back of a train.

(chiefly computer security) The use of direct observation, such as looking over someone's shoulder at an ATM, in order to obtain information.

The practice of riding on the top of elevator cars, outside the actual confines of the car.

The act of being carried over the heads of a densely-packed crowd, especially at a rock concert.

present participle of crowd surf

present participle of channel surf

present participle of body-surf

present participle of body surf

The act or practice of an individual who couch surfs.

present participle of couch surf