Professor Bill retrained a medic (8)
I believe the answer is:
academic
'professor' is the definition.
The definition and answer can be both people as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'bill retrained a medic' is the wordplay.
'bill' becomes 'ac' (abbreviation for account).
'retrained' indicates anagramming the letters (train can mean to shape or direct a plant).
'a'+'medic'='amedic'
'amedic' is an anagram of 'ademic'.
'ac'+'ademic'='ACADEMIC'
Can you help me to learn more?
(Other definitions for academic that I've seen before include "Scholarly (person)" , "what's not relevant" , "Associated with places of higher learning" , "Scholar - of no practical importance" , "Donnish" .)