Love interest of old city MD? (4)
I believe the answer is:
exec
'love interest' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.
'old city md?' is the wordplay.
I cannot really see how this works, but
'old' could be 'ex' (prefix meaning former or onetime) and 'ex' is found within the answer.
'city' could be 'ec' (the City of London postcode) and 'ec' is present in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
'of' acts as a link.
Can you help me to learn more?
(Other definitions for exec that I've seen before include "Business manager (abbr)" , "Board member" , "Senior administrator (abbr)" , "high-flier" , "big cheese" .)