He supplies personal cover (8)
I believe the answer is:
clothier
'he supplies personal cover' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'he' is the wordplay.
I cannot really see how this works, but
'he' could be 'hi' and 'hi' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for clothier that I've seen before include "Merchant who sells men's suits etc" , "who has particular habits?" , "Draper" , "Outfitter" , "Garment maker or seller" .)