Fellow I treated, is neatly groomed (9)
I believe the answer is:
manicured
'neatly groomed' is the definition.
'manicured' can be an answer for 'groomed' (manicuring is a kind of grooming). I'm unsure of the 'neatly' bit.
'fellow i treated' is the wordplay.
'fellow' becomes 'man' (fellow can mean a man).
'treated' becomes 'cured' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'man'+'i'+'cured'='MANICURED'
'is' acts as a link.
Can you help me to learn more?
(Other definitions for manicured that I've seen before include "given quick treatment?" , "well-groomed" , "digitally enhanced?" , "Digitally processed" .)