A switchback is a sharp turn in a trail or road that zigzags up or down a steep slope, making the climb more gradual and manageable. Instead of going straight up a mountain (which would be too steep to walk or drive), a switchback trail cuts back and forth across the slope in a zigzag pattern, like the letter “Z” repeated over and over.

Imagine climbing stairs versus climbing a ladder: stairs make the journey easier because they break the height into smaller steps. Switchbacks do the same thing for mountains and hills. Hikers ascending a tall peak might walk dozens of switchbacks, each one angling gently upward before turning sharply back in the opposite direction. The trail covers more distance this way, but the grade stays reasonable enough to climb without getting too tired or losing your footing.

You'll find switchbacks on mountain highways too, where roads loop back and forth up steep terrain. Drivers on some mountain roads navigate numerous switchbacks, turning their steering wheels hard at each sharp corner.

As a verb, switch back means to reverse direction or change course suddenly, like when a politician makes an unexpected switchback on a policy position.