One going on foot (4)
I believe the answer is:
shoe
'one going on foot' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe they are linked in a way I don't understand?
This is the entire clue.
Can you help me to learn more?
(Other definitions for shoe that I've seen before include "Case from which playing cards are delt one at a time" , "Pump, for example" , "Maybe court" , "Footwear - playing-card dispenser - part of a brake" , "Oxford, for example" .)