also top-rope
n.rock climbing or ice climbing term for when the climber is belayed by a rope fixed at the top of the pitch.
When the rope is properly anchored at the top most objective danger is removed from the route, allowing the climber to concentrate on solving the problem
If the rope is improperly anchored then the activity becomes very dangerous as should the anchor fail while the climber is on the rope then the climber will fall all the way to the ground.
A climb climbed on top rope cannot be regarded as properly climbed, it must be lead or soloed to gain that honour