Fix damage shoe nail regularly causes (4)
I believe the answer is:
heal
'fix' is the definition.
The definition and answer can be both related to bodily activities as well as being verbs in their base form.
Perhaps they are linked in a way I don't understand?
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for heal that I've seen before include "remedy" , "Cure, make well" , "Of wound, mend and get better" , "Cure, mend" , "Become healthy again" .)