[jak-shaft, -shahft] 
| 1. | Also called countershaft. a short shaft, connected by belting, gears, etc., that transmits motion from a motor or engine to a machine or machines being driven (distinguished from main shaft ). |
| 2. | a shaft on which an idle wheel or fairlead turns. |
| jack·shaft (jāk'shāft') n. A short shaft that transmits motion from a motor to a machine, especially in an automobile. |
