Medical men for instance within the grounds (5)
I believe the answer is:
dregs
'grounds' is the definition.
(synonyms)
'medical men for instance within' is the wordplay.
'medical men' becomes 'drs' (I can't explain this - if you can you should believe this answer much more).
'for instance' becomes 'eg' (short for 'exempli gratia', 'for example' in Latin).
'within' is an insertion indicator.
'drs' placed around 'eg' is 'DREGS'.
'the' acts as a link.
Can you help me to learn more?
(Other definitions for dregs that I've seen before include "Leftover drink, sediment" , "Wine or coffee residue" , "Sediment - rabble" , "Residue of drink" , "Remaining sediment" .)