A group of kneelers has to be withdrawn — they get worn by feet (5)
I believe the answer is:
socks
'feet' is the definition.
The answer and definition can be both man-made objects as well as being plural nouns.
Perhaps they are linked in a way I don't understand?
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for socks that I've seen before include "White horse's leg marks" , "Short stockings" , "Foot garments" , "Hose" , "Hard blows" .)