from The Century Dictionary and Cyclopedia
- n. A rod attached to the piston of an engine or pump and projecting through the head of the cylinder away from the crank. Such a rod helps to support and steady the piston, especially in an engine having a very long stroke.
Sorry, no etymologies found.
Two of these valves are placed in each piston of a double-acting air cylinder, the piston being hollow and the free air being admitted through a tail-rod pipe, letter E, Fig. 15.