1. 倒档：经济档 economic gear | 倒档 reverse gear | 爬行档 creeper gear

2. 倒挡：三挡 the third gear | 倒挡 reverse gear | 直接挡 direct gear

3. (中间轴)倒档齿轮：return tube 回油管 | reverse gear (中间轴)倒档齿轮 | reverse gear shaft 倒档轴

4. 倒挡齿轮：reverse gear clutch 回动齿轮离合器 | reverse gear 倒挡齿轮 | reverse idler gear 倒挡中间齿轮

noun

1. the gears by which the motion of a machine can be reversed

Synonym: reverse