To touch one's foot to the ground while bicycling. Considered to be a lost style point among trail riders, mountain bikers, bike polo players, among others. Since a lot of technical tricks can be avoided by simply walking the bike over a log or a stream, refraining from dabbing a foot encourages pure cycling and the attempt to negotiate obstacles by technical feats such as hopping or holding a track stand. Sometimes called a "foot down."
A term used in bouldering (rock-climbing on boulders) to denote hitting the floor or a friend with a body part while climbing. A dab can allow a climber to continue instead of falling off, so is regarded as invalidating an ascent (or "send")