Used to refer to someone who climbs, often used in a figurative sense.
El trepa logró alcanzar la cima de la montaña después de horas de esfuerzo.
The climber managed to reach the summit of the mountain after hours of effort.
El trepa que ves allí es un experto en escalar montañas difíciles.
The climber you see over there is an expert at climbing difficult mountains.