Hit on the foot (4)
I believe the answer is:
sock
This clue could be a double definition.
'hit' is the first definition.
(socking is a kind of hitting)
'the foot' is the second definition.
The definition and answer can be both man-made objects as well as being singular nouns.
I also know that 'foot' relates to this answer.
'on' acts as a link.
Can you help me to learn more?
(Other definitions for sock that I've seen before include "Item of footwear" , "bash" , "Hit hard - footwear" , "This partly protects member" , "one with wind" .)