I think of terrier work as coming from the era of gears and cogs, levers and tracks.
This was the period before microwave ovens but after we stopped cooking whole animals, bone in, over an open fire.
This was the period before cell phones, but after metal type and pulp paper made books and newspapers cheap and readily available.
Sprocket, Ratchet, Torque, Driver, Rocker, Gear, Spindle, Cog. These are all mechanical bits, but also excellent names for a working dog.