The hiking trail had several sharp switchbacks that forced us to slow down.

switchbacks 是复合名词，由 switch（转换）和 back（向后）组成，字面意思是"向后转换方向"。 在徒步或山路驾驶的语境中，switchbacks 特指"之字形急转弯"，这种设计通过反复改变行进方向来降低陡坡的倾斜度。