any of the small radiating bars inserted in the hub of a wheel to support the rim
any of the protruding knobs around the circumference of a ship's steering wheel
a rung of a ladder
put a spoke in somebody's wheel
to prevent somebody's plans from succeeding
[said to refer to the spoke or pin put through a hole in a solid cartwheel to slow it down when going downhill; or spoke may be a misunderstanding of the Dutch word spaak (meaning ‘bar’ or ‘stave’) used in the Dutch form of the phrase.]